Protzoology

PROTOZOOLOGY Protozoa are unicellular animals or organisms in which are performed all functions/activities of life – digestion, nutrition, respiration, reproduction, excretion, secretion, locomotion. They belong to the animal kingdom. (The other animals which are multicellular are metazoa). The comparable form of protozoa in the plant kingdom is the prophyta. Some organisms have characteristics of both plants and animals (kingdom protista). Living things are divided into five kingdoms, namely: 1. Animalia 3. Monera (algae, bacteria) 5. Protista 2. Plantae 4. Fungi Differences between prophyta and protozoa a. Morphology – prophyta have rigid and thick cell wall of cellulose and nuclear material dispersed in cell (prokaryotic). Protozoa have non-rigid and twin cell wall allowing marked variation in size and shape and well defined nucleus (eukaryotic) enclosed in a membrane. b. Method of nutrition – protophyta is basically holophytic. CHO’s are synthesized in the chlorophyll containing

c.

chromotophores (photosynthesis). Protozoa are basically holozoic. Utilizing preformed food materials derived from living plants or animals. Method of reproduction – prophyta divide by binary fission along transverse axis except in ciliates.

STRUCTURE OF PROTOZOA The two main components of a protozoan cell are the nucleus and cytoplasm.

1. Nucleus – usually single but some with two similar or

b. Compact or homogenous – little nucleoplasm and

dissimilar nuclei.

large amount of chromatin distributed throughout the nucleus. Found in ciliates.

Roles of the nucleus 1. Controls the life and activities of the cell 2. Stores DNA and RNA Types of Nuclei a. Vesicular – with a central body (endosome or karyosome or nucleolus). It consists of nuclear membrane which bound the nucleoplasm in which the central body (endosome (karyosome) or nucleolus) lie. Nucleolus is a ribosome factory. Nucleolus contains deoxyribonucleic acid – composed of chromosomes, responsible in the transmission of hereditary characteristics.

Two kinds Nuclei a. Micronucleus – controls reproductive function of the cell/organism. b. Macronucleus – controls vegetative function of the organism

2. Cytoplasm – two portions: the outer ectoplasm and the inner endoplasm. a. Ectoplasm – is a homogenous and hyaline in appearance. b. Endoplasm – contains granules, vacuoles, pigments, fluids, and organelles.

Cytoplasm is surrounded by the periplast (pellicle in ciliates). Organelles found in the cytoplasm are mitochondria (powerhouses of the cell that contain enzymes, final stage of respiration takes in). Ribosomes are site of protein synthesis, Golgi bodies (collected dehydrated proteins). Lysosomes (enzymes for digestion) while Contractile vacuole (responsible for eliminating of waste materials) and food vacuoles (digestion). Micron – is the unit for measurement 1 micron = 0.001mm 1000 microns = 1mm locomotion Protozoa may move by means of Pseudopodia, Flagella, Cilia or by Gliding

1. Pseudopodia (false feet) – these are temporary extrusion of 3. Cilia – fine, short flagella-like structures with axoneme, cytoplasm, formed and retracted as needed.

2. Flagellum/flagella – filamentous structures consisting of a central axial filament (axoneme) and surrounded by cytoplasmic sheath. Axoneme arises from the basal body or blepharoplast. In some species the flagellum passes along the undulating membrane. a. Ex. Trypanosoma sp., Trichomonas sp.

4.

cytoplasmic sheath and basal granule. May also function as tactile organs and aids in the ingestion of food. a. Ex. Balantidium coli Gliding – body glides smoothly without locomotory organelles a. Ex. Toxoplasma, Sarcocystis, Coccidia sporozoites and merozoites

PHYSIOLOGY OF PROTOZOA Nutrition of parasitic Protozoa 1. Holozoic protozoa utilize preformed food derived from living animals or plants. Food is ingested by pseudopodia or ingested either through permanent opening a cytosome or temporary opening in the body wall. Pinocytosis – ingestion of nutrient materials through temporary opening in the body wall. Food vacuole for digestion (ciliates). Some ingest host tissue cells (amoeba). Some have micropore (micropyle) for ingestion of fluids or solids.

2. Sporozoic protozoa – absorbs nutrients through the body wall by diffusing and utilizing directly by the organism.

3. Some are holophytic - Carbohydrates are synthesized on 4.

leaves of chlorophyll carried in chromotophores Autotrophic nutrition – live on organic compounds Phytoflagellates – proteins, carbohydrates, lipids are synthesized from organic compounds

EXCRETION OF PROTOZOA Either thru the body wall (by diffusion) or via the contractile vacuole or water vacuole more important as osmoregulatory organelle: 1. Regulate osmotic pressure within the cell in relation to fluid balance 2. Removal of excess water Indigestible materials are extruded out by temporary opening or permanent – cytpyge. Respiration: most protozoa utilize free molecular oxygen for respiration but many derived oxygen by splitting complex oxygen containing substances in tissue of host. Reproduction: may be asexual or sexual A. Asexual ( without male and female involvement) 1. Binary fission – most common method. Each individual divides into two daughter cells thru the long axis except ciliates (transverse) Ex. Trypanosomes – nucleus divides first followed by cytoplasm 2. Multiple fission (schizogony) – nucleus divides several times before cytoplasm does. Dividing cells are called schizonts, daughter cells – merozoites (schizozoites) in Coccidia, Plasmodia, etc.

3. External budding – a small daughter individual is

4.

separated off from the side of the “parent cell” and grows full size Ex. Babesia sp. Ectopolygent – more than two daughter cells are formed by external budding. Internal budding or endocyogeny Two daughter cells are formed within the mother cell and then breaks off destroying it

Ex. Toxoplasma sp. and Sarcocystis sp. B. Sexual (involvement of male and female individuals) 1. Conjugation – two individuals come together temporarily and fuse along one of their sides as in ciliates. Their macronuclei degenerate, micronuclei divide and one of the resultant haploid pronuclei passes from each conjugant (wandering) into the other conjugant (stationary) forming a synkarion, then separate and nuclear reorganization takes place. Synkarion nucleus divides, macronucleus is formed, and finally two new individuals are produced from each cell.

Ex. Balantidium coli Syngamy – two gametes of different sexes fuse to form a zygote which then divides by multiple fission to form sporozoites a. Isogamy – gametes are similar in appearance Ex. Babesia sp. In ticks b. Anisogamy – gametes are dissimilar Ex. Plasmodium sp. In mosquito

2.

Gametes are produced by special cells known as gamonts or gametocytes. The process is known as gametogony. The process of forming sporozoites is known as sporogony. Example: Coccidia Gametogony Syngamy Sporogony In plasmodia In the ground In mosquito Effects of Protozoan Infection in general 1. Absorb nutrients - Trypanosomes – glucose 2. Interfere with normal metabolism – Giardia – absorption of food 3. Production of toxin – Sarcocystis – sarcocystin

4. 5. 6.

Destroy tissues - Coccidia – haemorrhage Destroy blood cells – haemopoetic organs Premunity

CLASSIFICATION OF SUB KINGDOM: PROTOZOA Protozoa are classified into five phyla according to organ of locomotion I. a. b. II.

Phylum Sarcomastigopora Subphylum Sarcodina – with pseudopodia Subphylum Mastigophora – with one or more flagella Phylum Apicomplexia – produces spores, no organ of locomotion

III. IV. V.

Phylum Microspora – produce spores with polar filament Phylum Myxozoa – with amoeboid germinal elements in multicellular spores, Trypozoites are multicellular Phylum Ciliophora – with cilia

Subphylum Sarcodina Characteristics: 1. Move by means of pseudopodia 2. Cytoplasm distinctly differentiated into ectoplasm and endoplasm

3. 4.

Reproduction usually by binary fission (any plane) Nutrition is holozoic being predatory on bacteria, protozoa and some metazoa

Families: Family Amoedidae: free living amoeba. Occur in stagnant water/pools, soil, canal, etc. some may become pathogenic 1. Naegleria fowleri – causes “amoebic meningoencephalitis” in man. Route of infection – intranasally 2. Acanthamoeba culbertsoni – produce meningoencephalitis in mice and monkey if introduce intranasally. Family Endamoebidae 1. Contains parasitic amoeba which occur in the digestive tract of vertebrates and invertebrates. 2. Multiply by binary fission and form cysts Genus Endamoeba: 1. Nucleus with well define small endosome (nucleolus) 2. Occurs in vertebrate animals 3. Cysts contain 1-8 nuclei 4. Entamoeba species may be divided into 4 groups according to morphology of mature cyst.

a. b. c. d.

Cysts with 8 nuclei. ex. Entamoeba coli Cysts with 4 nuclei ex. Entamoeba histolytica Cysts with 1 nucleus ex. Entamoeba bovis Cysts with unknown number of nuclei ex. Entamoeba gingivalis

Entamoeba histolytica This is the only species of importance as a pathogen causing “amoebic dysentery” in man and monkeys. Occurs sometimes in dogs, rarely in cats, pigs and cattle. Morphology 1. The active trophozoite stage ranges from 10-60 microns in diameter. Produces long finger-like pseudopodia. 2. Endoplasm contains food vacuoles with RBC, WBC, tissue cells, etc. cysts are spherical ranging from 5-20 microns in diameter. Cysts are initially uninucleate but finally become tetranucleate with chromatoid bodies and glycogen vacuoles. Life cycle and Development: The trophozoite (active stage) multiplies by binary fission in the intestinal tract and liver of the host. Later, they become sluggish, ceased to feed and start to encyst. Cystic forms are passed out with the feces of the host. The stages are precystic, uninucleate cyst, binucleate cyst and tetranucleate cyst. The latter represents the mature and only infective form. Upon ingestion, the tetranucleate cyst encysts in the small or large intestine the newly released metacystic form undergoes division resulting in the formation of 8 young uninucleate amoebae. In the large intestine, they grow and invade the tissues. Two forms are recognized – the small and large forms.

Pathogenesis and Clinical signs 1. Only the large form of Entamoeba histolytica is pathogenic. Small forms are non-pathogenic. Tissue penetration is brought about by lysis of intestinal epithelium by proteolytic enzymes, trypsin and pepsin. 2. Following tissue invasion. The amoeba multiply, forming colonies, penetrate deeper to reach the submucosa and

3.

finally producing ulcer usually in the cecum and colon. There is usually enteritis with persistent dysentery (diarrhea), an excess of mucus and blood appearing in the feces. Frequent attempt to defecate with straining. Amoeba may enter the lymphatic vessels and mesenteric venules and invade other tissues of the body particularly the liver, lungs, brain and skin producing amoebic abscesses.

Epidemiology 1. E. histolytica is primarily a parasite of man. Infection is by ingestion of mature tetranucleate cysts. 2. Trophozoites may survive in water at room temperature for 5 weeks. Cysts are transmitted through contaminated food, or water, raw vegetables by flies.

Diagnosis 1. Finding cysts and trophozoites in the feces, stains with hematoxylin Flotation technique – using zinc sulfate solution Treatment (based on human therapy) 1. Etotamide Nimorazole (naxogin) 2. Fumagillin flagentyl (secnidazole) 3. Tinidazole (fasigyn)

4. 5.

2.

Clinical signs – persistent diarrhea/dysentery with or without mucus or blood in the feces Fluorescent antibody technique

3.

Diloxamide furoate (furamide) Metronidazole – drug of choice (flagyl: metroxyn) 2x daily for 510 days or more

Control 1. Good sanitation 2. Proper sewage disposal

3. 4.

6. 7.

Furazolidone Tetracyclines (chlortetracyclines & oxytetracyclines)

Personal hygiene Avoid fecal contamination of food and water

Other species are usually non-pathogenic: more of a commensal Entamoeba coli – colon and cecum of man, monkey, dog, pigs Entamoeba canibucalis – mouth of dog Entamoeba suis – digestive tract of pig Entamoeba bovis – digestive tract of cattle Entamoeba bubalis (dilimanni) – digestive tract of carabao Entamoeba ovis – digestive tract of sheep

Entamoeba gingivalis – mouth of man and dog Entamoeba equi – horse cecum and colon Entamoeba muris – rat Entamoeba caviae – Guinea pig Entamoeba cuniculi – rabbit

SUBPHYLUM MASTIGOPHORA Order Protomonadina Characteristics 1. With 1 or more flagella. A few have pseudopodia as well. Some have undulating membrane. 2. Nucleus vesicular Family Trypanosomatidae 1. Many are parasites of insects but others are heteroxenous (spending part of life-cycle in vertebrate and partly in invertebrate host) 2. Haemoflagellates are parasitic in the blood, lymphs and/or tissues of mammals and birds Morphology Developmental stage of Haemoflagellates 1. Trypanosome (trypomastigote) stage – leaf like kinetoplast post to the nucleus near the posterior end. Undulating membrane present. Occurs in the vertebrate host but also in arthropods as infective stage (metacyclic trypanosome) for vertebrate host. 2. Critidial (epimastigote) stage – leaf-like; kinetoplast anterior and near the nucleus. Short undulating membrane. Occurs in arthropods and vertebrate host.

3. 4.

Reproduction by longitudinal binary fission Many are free living and a few parasitic form cysts

3.

Leaf-like or rounded body with one nucleus and one flagellum. Undulating membrane present in some genera At least two development stages are undergone during the life cycle except in a few mammalian forms

4.

3. 4.

Leptomonad (promastogote) stage – leaf-like; kinetoplast near the anterior end. No undulating membrane. Occur in arthropods and plants. Leishmania (amastigote) stage – rounded/ovoid kinetoplast present but without free flafellum. Occurs in the vertebrate and arthropods. All stages may occur in the culture medium

Only two genera under family Trypanosomatidae are parasitic to domestic animals and man 1. Leishmania 2. Trypanosoma Genus Leishmania Characteristics 1. Heteroxenous 2. Parasite primarily of man, dogs, and rodents 3. Vector and transmitters are sandflies – Phlebotomus sp.

4. Leishmania form are found in macrophages, monocytes, polymorhonuclear leucocytes and endothelial cells of

5.

mammalian host, leptomonads occur in the intestine of sand flies All species are morphologically similar. They are differentiated only according to pathogenecity and geographical distribution.

Life cycle in general 1. Phlebotomus or sand fly ingest infected WBC (leucocytes) 2. Leishmania are liberated in the midgut ----- transform into leptomonad (promastigote) and multiply repeatedly by binary fission. 3. Finally leptomonads migrate to the esophagus and pharynx where they multiply further to the extent that they block the food canal.

Species of Leishmania 1. Leishmania donovani 1. Causes of “kala-azar”, visceral Leishmaniasis or “dumdum fever” in India, Africa, China, South America. 2. Man and dogs are principal hosts Pathogenesis and clinical signs 1. Highly fatal in man 2. The parasite multiply and destroy macrophages and endothelial cells of visceral organs 3. In chronic cases marked emaciation and anemia; distended abdomen due to hepatomegaly and splenomegaly 2. Leishmania tropica 1. Causes “cutaneous leishmaniasis” or “oriental sore” 2. Occurs in monocytes, polymorphonuclear, endothelial cells of skin of man, dogs and rodents in Africa, Egypt, India, Pakistan 3. Leishmania braziliense 1. Causes “American mucocutaneous leishmaniansis” or “espundia” in south America, “uta” in the mountains of peru 2. Host – man, dog, cat, mouse, rats

6. 7.

Round or oval, 2.0-5 x 1.5-2 microns Only the nucleus and kinetoplast are ordinarily visible in stained preparations

4.

When they fly feeds again, it dislodges the plug of organisms into the vertebrate host. Leptomonads invade macrophages and endothelial cells and finally transformed into Leishmania which also multiply by binary fission

5.

3.

Occurs in the macrophages and endothelial cells of blood and lymph vessels of spleen, liver, bone marrow, kidneys, lungs and skin.

4. 5. 6.

Ascites in advance cases In dogs cutaneous lesions – ulcer and eczema Mortality rate 75-95% if not treated; death occurring in few weeks to several years after infection.

3. 4.

Cutaneous ulcers may be “dry, moist or wet” Ulcers usually heal within a year living depressed pigment scar

3.

Occurs in the macrophages and endothelial cells of skin and mucous membranes of the nose, lips and pharynx. Granulomatous lesions and deformed earlobes

4.

Ulcers usually heal in 7-8 months but may last for 20 years

Diagnosis 1. Demonstrations of organisms from biopsy samples of spleen, bone marrow, lymph nodes, liver. 2. Stained scrapings from periphery of skin ulcers and eczematous areas. Treatment 1. Antimony compounds 2. Tartar emetic I.V. for 25-30 days Prevention 1. Control sandflies D.O.T., gammexane

5.

In extreme cases, nose, lips, soft palate and surrounding tissues completely destroyed.

3.

Culture of biopsy specimens on NNN medium (blood agar medium with locke’s solution) Formol-gel test Urea stilbamide test

4. 5.

3.

Nostibosan, solustibosan 10-12 days

4.

Stilbamide

2. 3.

Treatment of infected dogs, human cases Destroy stray dogs

4.

Control rodents

Genus Trypanosoma 1. Heteroxenous 2. May undergo four stages of development: trypanosome stage occurs usually in vertebrate host 3. Some are monomorphic, others polymorphic

4.

Transmission a. Cyclical by arthropods b. Mechanical by arthropods c. Both cyclical and mechanical

Trypanosoma species The genus is divided into 2 sections on the basis of morphology and life-cycle Section 1: salivaria (anterior station group). Transmission is thru insect bite Section 2: stercoraria (posterior station group). Transmission is thru insect fecal contamination of wound/mucous membrane Section 1: Salivaria group Morphology 1. Kinetoplast small, terminal or subterminal in position 2. Blunt posterior end 3. Free flagellum may be absent Biology 1. Trypanosome stage continue to multiply by binary or multiple fission in the vertebrate host 2. “Metacyclic trypanosomes” occur in the “anterior station” of the arthropod intermediate host (Glossina sp.) and

4.

3.

Undulating membrane varies in development

transmission is by inoculation or insect bite. Metacyclic trypanosome are the infective stage (smaller than those found in the vertebrate host). Often highly pathogenic

4.

Some species under this section mechanically only (non-cyclically)

are

transmitted

Example: T. evansi and T. equinum spp., T. equiperdum by coitus

Section 2: Stercoraria (posterior station group) Morphology (general) 1. Kinetoplast large and not terminal in position 2. Posterior end tapering Biology 1. Multiplication in the vertebrate host may occur in trypanosome, critidial or leishmanial forms (T. cruzi). Reproduction is usually with the criditial and leishmanial forms.

3. 4.

Free flagellum present Undulating membrane not well developed

2.

Posterior station development in the arthropods and transmission is by contamination with feces containing “metacyclic trypanosome” or trypomastigotes. Often non-pathogenic

3.

Pathogenecity of trypanosomes in general 1. Pathogenecity of trypanosomes varies with the species, strain and type of final host. Ex. In South Africa trypanosomes are generally not pathogenic to wild game animals which serve as reservoir hosts. In asia, T. evansi is not pathogenic to cattle and water buffaloes but highly pathogenic to horses. Clinical manifestations 1. Trypanosomiasis is usually a chronic disease characterized by intense anemia and emaciation. The usual clinical signs are interminent fever associated with accumulation of parasites in the blood (paroxysym of parasitemia). As the disease progresses, the number decreases and the clinical signs disappear except progressive loss of weight in spite of good posture and fairly good appetite. Edema of the subcutaneous tissue may be marked. 2. Tissue invasion - Some trypanosomes may be markedly invasive, it injures the wall of the blood capillaries, invades the bone marrow causing anemia. Heart muscles may be attached causing cardiac disturbances. It may also cause nerve lesions and capillary embolism. Transmission 1. Sucking flies: a. Mechanical – tabanids – Trypanosoma evansi b. Cyclic – tsetse flies – Trypanosoma brucei − feed contamination – Trypanosoma theileri

3. Blood changes - The most noticeable pathological change is

4.

progressive anemia which is due to failure in production rather than destruction of the RBC. As the disease progresses, there is hypoglycaemia due to exhaustion of glucose glycogen reserves. Cause of death - One theory is that in severe infection, there is decrease in blood sugar accompanied by increased lactic acid concentration in the blood. The increase lactic acids causes asphyxia by interfering with the absorption of oxygen by the haemoglobin. Another theory is that destruction of the glucose throws a stain on the liver which results in liver disfunction and a resulting toxaemia.

2. Coitus – Trypanosoma equiperdum 3. 4. 5. 6.

Intrauterine Milk/colostrums Ingestion of infected blood organ Needly passage: blood transfusion

Section Salivaria (anterior station forms) a. cyclically transmitted forms b. mechanically transmited forms A. cyclically transmitted forms 1. Trypanosoma vivax

2.

Trypanosoma uniforme

3.

Trypanosoma. congolense

Hosts: Principally ruminants (cattle, buffaloes, sheep, goats) but all other animals are affected, wild game animals act as reservoir. Distribution – Africa, Central and South America Transmitters – tsetse flies (Glossina morsitans, G. palpalis, G. tachinoides) Pathogenecity – mild diseases in cattle, sheep, goats In horses – chronic course; low/depress spirit (nagana), anemia, weakness, Emaciation, edema of subcutaneous tissues and swollen lymph nodes Diagnosis – 1. lymph nodes smear 2. blood smear

4. Trypanosoma simiae – polymorphic 5. Trypanosoma suis – monomorphic

6.

Host: pigs, warthogs, camel Distribution: Africa Transmitter – tsetse flies (Glossina sp.) Trypanosoma brucei

Morphology - Polymorphic (slender, stumpy and intermediate forms) Undulating membrane – conspicuous Distribution: Africa Host – horses, mules, donkeys, camel, dogs, sheep and goats are very susceptible Causes fatal disease known as “nagana” Cattle and pigs are resistant Transmitter – cyclically by tsetse flies (Glossina palpalis and G. moritans) also mechanically by biting flies (Tabanus and Stamoxys) Pathogenecity: 1. Causes severe disease in equine, may cause death in 4-8 days after infection, but usually 2 weeks to few months

2.

Diagnosis: 1. Blood smear: thick smear in chronic form 2. Lymph node smear 3. Mouse inoculation – may be patent in 3-4 days 7. Trypanosoma gambiense Causes “Gambian sleeping sickness” in man or human “trypanosomiasis” Morphology: similar to T. brucei Transmitted by tsetse flies Host – man in Africa 8. Trypanosoma rhodesiense

Important signs – anemia, lethargy, dullness, prostration: (nagana) loss of condition, muscular stiffness, unsteady gait, corneal opacity and edema of the legs and abdomen. a. b. c. d.

e. f.

Causes Rhodesian or African sleeping sickness in man Human trypanosomiasis Affects wild and domestic animals (zoonotic) Transmitted by tsetse flies Morphology similar to T. brucei All the species transmitted by tsetse flies. Development occurs in the midgut and proboscis

B. Non-cyclically or mechanically transmitted forms A. Trypanosoma evansi Morphology: a. monomorphic b. kinetoplast – subterminal c. undulating membrane – well developed d. free flagellum well developed Hosts: horse, dogs, camel, carabao, cattle, pig, cat, other mammals Distribution – widely distributed in the far east, near east, Philippine, central and south America, Indian subcontinent. Transmission: Mechanically by Tabanus sp. (Stomoxys, Haemotobia, Lyperosia spp) because of their interrupted feeding habits. Dogs may be infected by ingestion of infected blood or organs. Pathogenecity and Clinical Manifestations: 1. The most severe disease occurs in horses, camel and dogs. This is the most pathogenic protozoan parasite of horses in the Philippines. The disease in horses is called “surra” a hindu word meaning “rotten”. It is always fatal if not treated. The most common signs are anemia, emaciation in spite of fairly good apetite, edema of the legs and lower parts of the body (breast and abdomen). Intermittent fever, weakness of the hind quarters, dullness, prostration, droopiness and sometimes stiffness of one or both legs. Urticarial plagues may appear in the neck and flanks which may necrose in the center. 2. In cattle and carabaos, occasional outbreaks may occur. In acute cases animals may die suddenly following stress even in apparently healthy animals with blood teeming with trypanosomes. In the bull, there may be edema of the

3.

4.

scrotum and loss of condition even if kept in good pasture. In general, cattle and carabaos carry the organisms without showing any clinical signs hence they serve as reservoir host. During summer when pasture is dry, cattle may succumb to infection. On post-morthem, the important gross lesions are enlarged spleen and lymph nodes, anemia, emaciation, congested liver, kidneys, etc. in pig – chronic form. In dogs – T. evansi is highly fatal causing emaciation, weakness, and edema but may run a chronic course, 6 months or more. In camel, it is a chronic course which may last for 3 years or more characterized by emaciation. In Sudan they call it “gufar”. In elephant “surra” is a chronic type characterized by emaciation and weakness. In Panama it is called “murina” in

horses, and in Venezuela, “derrengadera” in horses; Philippines – “Bayawak” in horses. Diagnosis 1. Clinical signs 2. Blood smear examination in acute form – direct smear; stained smear 3. Biotest or laboratory animal inoculation in chronic type – 25cc of blood to rats I.P. 0.5-1ml in mice I.P. guinea pig, rabbits more blood IP to cat and dog

4.

Serologic tests a. mercuric chloride test – consist of adding one drop of suspected serum to 1ml of a 1:30,000 solution of mercuric chloride in distilled water. A white opalescence indicates infections of one or more month standing

B. Trypanosoma equinum Monomorphic Similar to T. evansi except the axoneme arises from the small blepharoplast. Distribution – central and south America Hosts – chiefly equines, being most seriously affected causing “mal de caderas” (bad hind quarters) Transmission - Mechanical by Tabanus, Stomoxys and Lyperosia spp Pathogenecity 1. Causes emaciation, marked weakness of the hind quarters “ mal de caderas” resulting in staggering gait. Finally animals become recumbent and die in few weeks; 2-6 months in chronic form. Causes high mortality in equines. Diagnosis 1. Blood smear emacination – direct, stained

2.

In post-morthem, the spleen and lymph nodes are enlarged and cadaver is extremely anemic.

2.

Lab animal inoculation – dogs, cats, rabbits, mouse, rats

C. Trypanosoma equiperdum Causes a veneral disease called “dourine” (Arabic term for “unclean”) or “mal de coit” Morphologically identical to T. evansi Distribution – Asia, north and South America, south eastern Europe Hosts – horse and ass Transmission 1. Usually through coitus 2. Rarely by biting flies

3.

Contamination of mucous membrane

Clinical signs: the Disease progresses thru 3 distinct phases following incubation period of 2-12 weeks or several months I. Stage of edema May persist for few hours or 3-4days, then disappear but may Mucoid vaginal or urethal discharges, or a degree of reappear again. Plaques are almost pathognomonic of nymphomania, mild fever, with edema of genitalia, chest and “dourline” or “mall de coit” belly. III. Paralysis II. Urticarial phase Muscle of the face and nostrils are usually affected followed Appearance of edematous “plaques” under the skin. Plaques with complete paralysis and recumbency then death. Mortality are circumscribed, 1-4 inches in diameter (“dollar spots”) is 50-70% if not treated. since they appear as if a silver dollar is inserted under the skin. Diagnosis 1. Clinical signs 2. Parasite not readily detected in the blood 3. Examination of vaginal and preputial discharges or fluids of urticarial plaques

4. 5.

Laboratory animal inoculation C.F test

Section stercoraria (posterior station forms) Transmitted by contamination with feces. Not very pathogenic. Does not multiply fast. A. Trypanosoma theileri Hosts – antelopes, cattle, carabaos, buffaloes Distribution – in the Philippines Transmitted – clinically by Tabanus sp., Haematopota sp. Has been associated by “turning sickness” in Uganda, associated with abortion, and decrease milk yield

may interfere with surra diagnosis. It is bigger than T. evansi. 65% prevalence in cattle and carabaos on culture. Negative on mouse test. Blood concentration technique – microhematocrit

B. Trypanosoma melophagium – sheep - cyclically transmited by Melophagus ovinus or sheep ked

C.

Trypanosoma lewisi – rats

Transmitted cyclically by rat flea – Ceratophilus fasciatus common in P.I.

D. Trypanosoma canorini – monkeys, rats, common in P,I Intermediate hosts – Triatoma or kissing bugs

E. Trypanosoma cruzi Causes “chagas disease” in man Distribution – south America Morphology: cresent-shaped Kinetoplast usually large

SUBTERMINAL Host: Man Reservoir: dog, cat, pig, foxes, monkeys, opossums, armadillo Transmitter: Cyclically by Triatoma sp. Infection is thru contamination of wounds, m.m., nearly the eyes or lips where they usually feed. Clinical signs: 1. Edema at the site of bites 2. Death may occur in 2-4 weeks in acute form in children 3. Chronic form in adult is characterized by debility, anemia and splenomegaly Diagnosis: 1. blood smear in acute form 2. chronic form- sub-inoclutation to guinea pigs

4.

Affection of the heart result in degeneration of cardiac muscle, central nervous involvement in others

3. “Xenodiagnosis”: Feeding Triatoma on the suspect or allowing bugs to feed on patient blood. Laboratoryreared Trypanosoma cruzi- free bugs are used. Then

examinations of the bug 7-10 days post-feeding metacyclic trypanosomes are present in feces or in digestive tract. Avian Trypanosomes 1. Trypanosoma avium- birds

4. 5.

Complement Fixation Test (C.F.T.) Culture media

2. Trypanosoma gallinarum- chickens

3. rypanosoma. calmetti- ducklings

2. Trypanosoma miyagii- frogs

3. Trypanosoma palawanense- rat

Other species reported in Philippines 1. Trypanosoma chattoni- frogs Treatment of Trypanosomeiasis

Trypanosomicidal drugs may be curative or prophylactic in nature. 1. Tartar emetic (old treatment)- 1 gram in 20-35 ml saline solution given I.V. 6-8 times at weekly intervals. Necrosis may occur if the drug leaks from the vein 2. Suramin (Naganol)- 7-10 mgs/kg in 10% solution. I.V. Single dose or in divided doses for 3 weeks. To T. evansi, 1-2 grams/100 kgms B.W.

3.

4. 5.

Antrycide a. antrycide methyl sulfate 3 mg/kg in 10% solution, sub-cutaneous b. antrycide chloride (prosalt) 12 mg/kg protection – 70 days Ganaseg- 2-4 mg/kg, body weight of a 5% solution, intra-muscular berenil Trypamidium (Isometamedium)- 0.5-1 mg/kg, body weight, intra-muscular/ intravenous

In the control of Trypanosomes, the following factors should be considered: 1. Drug resistant strains- recurrence after treatment 4. Mechanical transmitter- Tabanus, Lyperosia and Stomoxys 2. Reservoir hosts- wild game animals, domestic animal in the 5. Feeding of infected raw blood/organs, most probable cause case of some Trypanosomes of infection in dogs with T. evansi 3. Interior host- Tsetse flies (Glossina morsitans, G. palpalis, 6. Mass vaccination- use of different needles G. tachinoides), kissing bugs, Triatoma sp.; shepherd (M. 7. Blood transfusion ovinus), etc. Order Polymastigida Characteristics: 1. 3-8 flagella 2. One or more nuclei

3. 4.

One or two axostyles present Multiply by binary fission

5.

Cysts are produced in some forms

Family Trichomonadidae Morphology: 1. Pyriform in shape 2. 3-5 anterior flagella

3. 4.

One posterior flagellum Undulating membrane

5. 6.

Cysts are not formed One nucleus, one axostyle

Genera: Tritrichomonas- 3 anterior flagella Trichomonas- 4 anterior flagella Pentatrichomonas- 5 anterior flagella Genus Tritrichomonas Tritrichomonas foetus- occurs in the genital tract of cows and in the preputial cavity of as bovine trichomoniasis which is characterized by infertility, pyometra and abortion. Morphology: 1. 15-25 μm in size

2.

3 anterior flagellum

flagella,

one

Clinical Signs: 1. Early signs are vaginitis and periodic mucopurulent vaginal discharge. Purulent endometritis, there may be prolonged anestrus with pyometra due to early death of the fetus. Fetus may not be expelled but macerated.

posterior

3.

bulls. It causes a venereal disease known

undulating membrane runs the whole length of the body

2. Placentitis frequently develops resulting in the detachment of the placental membranes and death of the fetus. This leads to abortion which is typically early (not later than the 16th week after service). If abortion occurs too early (1-2

3.

weeks after service) fetus and membranes may be expelled unnoticed. In the bull, the signs are slight swelling of the prepuce, pain during micturition or service and the bull may refuse to

Transmission: 1. Coitus 2. Artificial insemination

mount the female. As the condition becomes chronic, pain and swelling disappear.

3.

Instruments, hands, gloves during veterinary examination

Epidemiology: Once the bull is infected, it should be regarded as permanent source of infection (carrier). In the cows, however, the disease is self-limiting or self-cure (parasite may disappear completely and may conceive without fear of abortion later). Diagnosis: 1. Herd history. Trichomoniasis should be suspected when: a. Cow requires several services b. Failure to conceive c. Early abortion d. pyometra 2. demonstration of organisms from the following: a. stomach of aborted fetus b. amniotic fluid c. discharges following abortion d. washings from vagina e. mucus from anterior end of vagina (most abundant 14-18 days after service/infection) f. preputial washings Introduce 100 cc of saline solution or 5 dextrose in saline into the preputial cavity. Treatment: 1. Washing with either 4-5% sodium perborate or 1-3% lugols or chlorine solution 2. Application of 1% acriflavine solution or ointment to the penis of preputial sheath injected into the urethra 3. Ganaseg 1% SOLUTION. Introduce 100-150 ml to the preputial cavity. Let it stand for 15 minutes. Massage thoroughly Prevention: 1. slaughter of infected bulls and cows (carriers) 2. avoid practice of communal bull

Close orifice, massage, collect, centrifuge and examine sediment. Organisms present intermittently- repeat examination as necessary. 3 negative result. 3.

Serological test a. Blood agglutination test- blood mixed with antigen (T. foetus culture) b. Mucus agglutination test- mucus from vagina is mixed with glucose saline – diluted- mixed with suspension of T. foetus ---- + agglutination Culture in diamonds media or beef extract glucose- peptone serum (BGPS)

4.

4.

Sodium Iodide- given at the rate of 5 grams/100 lbs body weight. Intra-venous; 5 consecutive doses at 48 hours intervals (given concurrently with local treatment) Dimentridazole P.O./I.V. or injected into the urethra in bull

5.

3. use of clean bulls for A.I.. T. foetus may survive in frozen semen.

Tritrichomonas suis- gastro-intestinal tract and nasal passages of pigs Tritrichomonas equi- cecum, colon of equine

GENUS Trichomonas Trichomonas gallinae Causes “avian trichomoniasis” of upper intestine of pigeon in particular. Chickens, turkeys and other birds may be affected. It causes a serious disease of pigeons. Morphology: 1. pyriform 2. 5-10μ in size

3.

Symptoms: 1. great majority of pigeons (80-90%) 2. may carry T. gallinae without showing signs

with 4 anterior flagella

3.

4.

V.M. ends at about 2/3 of the body

acute outbreaks may occur in squabs characterized by weakness and death

Pathogenesis: The earliest visible lesions are yellowish nodules which increases in size until the mouth, eosophagus and trachea are blocked. Nodules are also found in the crop and proventriculus. Nodules contain caseous materials “yellow buttons” filled with T. gallinae. Pigeons become emaciated due to failure to ingest feed. a. “pigeon’s milk” b. Contaminated drinking water c. Contaminated feed Diagnosis: a. Occurrence of characteristic nodules in the mouth cavity, esophagus and crop

b.

Demonstration of organisms from mouth and crop contents or caseous materials

Treatment: 1. Enheptin- 30mg/kg daily for 7-14 days 2. Dimetridazole

3.

Furazolidone- 25-30 mg/day for 7 days. Carrier adults should be treated

Trichomonas gallinarum- occurs in lower intestine and liver of chickens in particular. May occur in other birds. Morphology: 1. pear shaped 2. 6-8 μx 9 x 12μ

3. 4.

4 anterior flagella posterior flagellum ends at about the same point as the tip of the axostyle

Symptoms: As a rule, it is not very pathogenic Liquid pale yellow diarrhea Nuffled feathers, loss of weight, loss of appetite Pathology: Trichomonas gallinarum produces circular necrotic lesions of the liver similar to histomoniasis. Lesions have irregular outline and raised surfaces. Transmission: Ingestion of contaminated feed and water Treatment: 1. Enheptin (2-amino-5-nitrothiazole) 0.1% of the feed Other species: Trichomonas anseri- ceca of geese Trichomonas anatis- ceca of duck Trichomonas ovis- cecum of sheep Trichomonas felistomae- mouth of cat Trichomonas canis- intestine of dog Trichomonas vaginalis- vagina, prostate and urethra of man. Laboratory animals causes vaginitis

2.

Furazolidone- 25-30 mg/kg with the feed

Trichomonas tenax- mouth of man, monkeys (between gum and teeth). Most commonly associated with dental disorders and pyorrhea Pentatrichomonas hominis -5 anterior flagella. Intestine of man, monkeys, gibbon and other animals

FAMILY HEXAMITIDAE General Characteristics: 1. binucleated without undulating membrane 2. 8 flagella produce cysts 3. 2 needle-like axostyles

4.

reproduce by binary fission

Genus Hexamita Hexamita meleagridis- small intestine of turkeys, causing a condition known as Hexamitiasis or Catarrhal enteritis Morphology: 1. pyriform 2. bilaterally symmetrical 3. 2 nuclei Symptoms: 1. a disease particularly of young turkeys 2. mortality may reach 80%

4. 5. 6.

6 anterior flagella 2 posterior flagella 2 axostyles 3. 4.

7. 8. 9.

multiply by binary fission moves very rapidly cyst is formed with fibrils

affected birds appear nervous, depressed, ruffled feathers with foamy, watery diarrhea loss of condition, dehydration and death

Pathology: Catarrhal • inflammation of the intestine • intestinal contents are thin, watery and foamy Diagnosis: 1. demonstration of organisms in freshly killed birds

2.

organisms are difficult to demonstrate in birds 1-2 hours after death

Treatment: 1. Furazolidone- 50 mg/lb of feed 2. Oxytetracycline- 25 mg/lb feed 3. Chlortetracycline- 200 mg/lb feed

4. 5.

Nithiazide- 0.02% of drinking water Enheptin- 30 mg/kg body weight for 7 days

Prevention: 1. raise young poults away from adults 2. general cleanliness

3.

treatment of carrier adults

Hexamita columbae - pigeon Genus Giardia Giardia lamblia (intestinalis)- occurs in the small intestine of pig, monkey and man causing a condition known as “giardiosis”. Common in Philippine Island. Morphology: 1. bilaterally symmetrical 2. pyriform 3. with 2 nuclei 4. 2 axostyles

5. 6. 7.

two well developed sucking disk 8 flagella convex dorsally and concave or flattened ventrally

Symptoms: 1. most cases are asymptomatic 2. chronic diarrhea 3. there may be large amount of mucus in the feces but no blood Pathogenesis: Diarrhea and dysentery Diagnosis: 1. demonstration of trophozoites and cysts in the feces Treatment: 1. Atabrin, quinacrine

2.

Chloroquin

3.

Camoquin

4.

Metromidazole

Giardia canis- dogs, Philippine Island G. cati- cats G. bovis- cattle G. caprae- goats

ORDER RHIZOMASTIGIDA General Characteristics: 1-4 flagella with pseudopodia FAMILY MASTIGAMOEBIDAE Genus Histomonas Histomonas meleagridis • Occurs in the liver and ceca of turkeys, chickens, quail, pheasant peafowl, partridge

•

A serious disease of turkeys causing a disease known as “histomoniasis”, enterohepatitis or “black head”

Morphology: 1. pleomorhic 2. 8-15μin diameter 3. one nucleus 4. large endosome 5. no axostyle 6. no undulating membrane Transmission:

7. 8.

cysts are not formed reproduce by binary fission 9. in the lumen of the ceca, it has 1-4 flagella 10. in the liver and cecal tissue, they are actively amoeboid with blunt rounded pseudopods (no flagella) 11. may occur singly or in cluster

•

Infection is either direct by ingestion of infected feces or indirectly through ingestion of infected Heterakis eggs or infected earthworms. (Heterakis are cecal worms, Histomonas are attracted by the developing heterakis ova, becomes enclosed by the egg shell. Earthworms can transmit Heterakis eggs with Histomonas)

Epidemiology: • Chickens are important reservoirs • May carry the organisms without showing signs

•

•

Earthworms may harbor Heterakis eggs with Histomonas for long period

3. 4.

vent smeared with sulfur yellow feces droopiness, ruffled feathers, loss of appetite

• • •

It is more of a disease of young turkeys 3 to 12 weeks of age Chickens are resistant Losses 50-100%

Infected Heterakis eggs may survive in soil for 1-2 years

Symptoms: 1. combs and wattles may become cyanotic (black head) 2. sulfur-yellow droppings Pathogenesis: • In the liver, characteristics are circular, depressed, yellowish areas of necrosis (the various sizes of a 50 centavo coin) one to three cm. occur • These are the pathognomonic lesions: the ceca ulceration and neorosis of the cecal wall which become thickened, containing yellowish caseous exudate. Diagnosis: 1. Clinical signs, sulfur-yellow droppings is very suggestive 2. Pathological lesions, necrotic lesions of the liver and cecum Treatment: 1. furazoline 2. enheptin Prevention: 1. do not raise turkeys with the chickens 2. remove droppings regularly

3.

Histologic examination of liver and cecal section and finding organisms

3. 4.

carbasone nithiazide

5.

dimetridazole, ronidazole

3.

pasture rotation at regular intervals elevated waterers and feeders phenothiazine with the feed

6. 7.

raise turkeys on wire floorings continuous medication with the feed with the above therapeutic agents

4. 5.

Phylum Apicomplexia Class: Sporozoa • no organ of locomotion except in the gamete stage • produces oocysts, spores and sporozoites • reproduced:

a. b.

asexually by binary fission or multiple fission (Schizogony) sexually by gametogony/syngamy and sporogony

Subclass: Coccidia • parasites of the epithelium of the digestive tract and related organs chiefly of vertebrates Two important families: 1. Family Eimeriidae 2. Family Sarcocystidae FAMILY EIMERIIDAE Schizogonic, gametogonic and syngamy take place in one and the same host. Sporogony occurs outside the host. No intermediate host. A macro and microgametocyte develop independently. One macrogametocyte develops into one macrogamete while one microgametocyte develops into several microgametes.

A zygote is formed by the union of one macrogamete and one microgamete. The zygote secretes membrane (cyst wall) around itself and becomes an oocyst. By a process known as sporogony, a variable number of spores or sporocysts are formed. Sporozoites are produced in each spore/sporocyst. The different gene5ra of the Family Eimeriidae are differentiated by the number of spores or sporocysts and sporozoites in each sporulated oocysts. Six genera of veterinary importance are the following: 1. Cryptosporidium 4. Eimeria  No sporocyst or spore  4 sporocysts  4 sporozoites  2 sporozoites in each sporocyst 2. Tyzzeria 5. Wenyonella  No sporocyst or spore  4 sporocysts  8 sporozoites  4 sporozoites in each sporocyst 3. Isospora 6. Klossiella  2 sporocysts or spores  No spore  4 sporozoites in each sporocyst  Produce sporoblast/sporozoites Life cycle of Coccidia in general: The asexual phase (Schizogony) starts with the trophozoite, a round or oval body inside a tissue cell. The trophozoite enlarges, nucleus divides into several nuclei which leads into the formation of a schizont. Each nucleus acquires a small portion of the cytoplasm resulting in the formation of spindle-shaped and motile merozoites. Affected host tissue cell ruptures releasing the first generation merozoites. Some merozoites invade other tissue cells and repeat the process of schizogony producing second generation schizonts. This process may be repeated several times. As a possible response to developing immunological reaction, some merozoites become differentiated into male and female forms and the sexual phase of the life-cycle is initiated. The sexual forms are known as gamonts or gametocytes. The male form (microgametocyte), divides into several motile microgametes while the female form (macrogametocyte) develops into a single macrogamete. One microgamete fertilizes a macrogamete to form a zygote. The latter secretes a cyst wall and becomes oocyst. The oocyst is extruded from the host tissue and pass to the outside with the feces. This is the resistant stage in the life cycle. In the ground, the oocyst sporulates (sporogy) to form sporoblast which latter develops into sporocyst or spore. Sporozoites are formed inside each sporocyst. In Eimeria, 4 sporocysts or spore develop, each with 2 sporozoites. In Isospora, 2 sporocysts each with 4 sporozoites are formed. Sporulated oocysts are infective. Infection is through the ingestion of sporulated oocyst with contaminated feed and water or feces. In the intestinal tract, the oocyst exists and the sporozoites are released. Sporozoites enter epithelial cells (host cell) and the schizogonic process is repeated.

Pathogenesis: Depends on: • number of Schizogonic generations • size of infective dose Destruction of the host cells leads to: 1. Diarrheal enteritis with or without bloody droppings

• •

number of merozoites host resistance

•

type of host cell affected

2.

Discharge of large amount of mucus Poor weight gain, stuntedness

4. 5. 6.

Poor feed conversion Weakness, emaciation, anemia death

3.

Immunity: Specific resitance to reinfection is characteristic of Coccidiosis. In chickens, resistance to further infection begins to develop sometime after exposure. In layers, mild gradual exposure to Coccidia is necessary to produce immunity. Epidemiology: In general, adults are resitant to Coccidiosis, young stock are highly susceptible. Infective (sporulated) oocysts are resistant and can survive long period of time. Transmission is thru water and feed contamination. Mechanical vectors are flies, beetles, rodents, man and animals. Diagnosis: 1. Clinical manifestations

2.

finding large number of oocysts in the feces

Treatment: I. SULFONAMIDE PREPARATIONS SULFAMERAZINE SULFAQUINIDINE SULFAQUINOXALINE SULFAMONOMETHXINE SULFAMETHAZINE Prevention: 1. coccidiostats with feed/water amprol pul; clopidol, robenicdine 2. avoid overcrowding

3.

pathognomonic lesions on autopsy

II. COMMERCIAL SULFA PREPARATIONS BELMET SULQUIN TRIOS ESB POWDER ABIZET RE-O-SAL SULMET

3. 4. 5.

regular removal of droppings (daily/twice a week) maintain cleanliness mild exposure to produce immunity

Difference between Coccidiosis and Coccidiasis: coccidiosis – a clinical disease condition cause by coccidian (eimeria, isospura, etc.) and treatment is needed coccidiasis – the presence of oocyst in the intestinal tract without producing clinical manifestation (subclinical infection). Treatment is not necessary Coccidia of mammals In general, coccidial infection in mammals is not a problem. It usually occurs as mild infection. Many animals harbor oocysts without showing clinical signs (coccidiasis). Coccidia of Cattle, Carabaos, Buffaloes. 1. Eimeria zuernii – most pathogenic. Small and large intestines 2. Eimeria bovis – next to E. zuernii in pathogenicity Clinical signs 1. Calves below one year – usually infected

3. Eimeria auburnensis – cause mild coccidiosis 4. 5.

Eimeria ellipsoidalis Eimeria bukidnonensis

2.

Watery diarrhea with mucus and blood

3. 4.

Tail and hind quarters soiled with feces Abdominal pain and straining during defecation

Diagnosis 1. finding oocysts in the feces 2. clinical signs Treatment 1. Sulfonamides

2.

3.

5.

Loss of appetite, dehydration, loss of weight, death

smears from the mucosal scarpings on ost mortem

Amprolium

Coccidia of sheep and goat

• •

Eimeria ahsata – most pathogenic Eimeria faurei – mildly pathogenic

•

Eimeria arloingi – most common

• •

Eimeria crandallis Eimeria granulosa

Clinical Signs Clinical coccidiosis is confined only to young animals (Kids and lambs). Significant sign is diarrhea. Mortality rate with E. arloingi. May reach 10%. Coccidia of swine Usually occur in low grade infection (Coccidiasis). Generally not pathogenic 3. Eimeria scabra 1. Eimeria debliecki – most common 4. Isospora suis 2. Eimeria spinosa Clinical Signs Profuse Diarrhea, may occur concurrently with colibacillosis/scouring in piglets Coccidia of Horses Occurs in low grade infection 1. Eimeria leuckarti 2. Eimeria solipedum

3. 4.

Eimeria uniungulati Klossiella equi

Coccidia of Dogs and Cats Eimeria canis Eimeria felina Eimeria cati

Isospora canis Isospora bigemina (now Sarcocystis bigemina) Isospora rivolta Isospora felis Normally, the oocysts are unsporulated when voided with the feces.

In Isospora felis and Isospora rivolta extra-intestinal tissue forms (zoites) are seen in the liver, brain, spleen, lymph nodes of cats, puppies and even in rats and mice. This peculiarity is also exhibited by Toxoplasma normally and therefore interfere with correct diagnosis. Clinical signs 1. bloody diarrhea

2.

weakness

Coccidia of rabbits Pathogenic species 1. Eimeria perforans 2. Eimeria media – G.I. tract causing diarrhea 3. Eimeria magna, Irresidua C.S.I Rats 1.

Eimeria separata, E. nieschultzi

Mouse 1. Eimeria falciformis 2. Cryptosporidium muris, C. parvum G. Pig 1. E. cavial colon 2. Cryptosporidium wrairi

3.

anorexia

4.

5.

4.

Eimeria intestinalis E. stiedai – liver (bile ducts)

emaciation and death

Klossiella kobayae – kidney Fish

1. Eimeria aurata – gold fish

2. E. carpelli – carp

3. E. cyprinid – carp

4. E.

truttae salmon

–

Diagnosis, Treatment and Preventation – the same as that of cattle COCCIDIA OF POULTRY Coccidia of Chickens Coccidiosis of chickens is of great economic importance. Heavy mortality occurs in severe infection. Subclinical infection – common, no mortality but causes poor feed conversion, poor weight gain and low egg production. More or less organ specific 1. Eimeria tenella – most common and most pathogenic species causing “cecal” coccidiosis. Usually affects chicken 3-5 weeks of age. Mortality may range from 80-90% in severe untreated cases

Clinical signs: • Bloody droppings (most significant sign

• •

Anemia Weakness

Pathology 1. Hemorrhagic ceca – the most significant lesion. Severe hemorrhages occur 5-6 days post-infection. If the bird survives 48 hours following hemorrhage, “cheesy necrotic core” (accumulation of clotted blood, tissue debris and oocysts in the ceca persist. Occysts are produced and seen more abundantly on feca. Examination 9-11 days after infection. Mortality is highest between the 4th and 6th day post infection. Continues mild exposure induce strong immunity. Other species:

• •

Dehydration Death

2. Eimeria necatrix – next to tenella in pathogenicity. Causes distention of the middle intestine (ballooning). 2-3 times the normal diameter. Filled with unclotted blood. Affects even older birds/layers may die of severe infection. 8-12 weeks or older, induce poor immune response.

• • •

Eimeria acervulina – duodenum, characterize numerous gray or whitish transverse pathes. Eimeria praecox – duodenum

by

Eimeria hagani – duodenum; less pathogenic

• • •

Diagnosis: 1. finding large number of oocysts 2. clinical manifestations 3. post-mortem exam of some birds: a. Hemorrhagic ceca – E. tenella

Eimeria mivati – duodenum; middle intestine Eimeria maxima – S.I. qualification necrosis/ sloughing of the mucosa Eimeria mitis – S.I., cecum less pathogenic

b. Distended or ballooned middle intestine – E. necatrix

c. Hemorrhagic duodenum – E. acervulina d. Sloughing of mucosa – E. brunette

Treatment • Sulfonamides a. Sufamonomethozine (Daimeton soda) b. Sufamethazine c. Sulfaquinoxaline d. Sulmet – sodium sulfamethylpyrimedine

e. f. g. h. i.

Sulfanonomethoxine Belmet – sulfanerazine, sulfamethazine ESB power (sulfachloropyrazine) Sulquin 6-50 solution Abizet

sulfadiazine,

Medication – 3-2-3 program (3 day treatment 2 days non-medication and 3 days medication) Prevention: 1. continuous medication with the feed using coccidiostats (inhibitory) coccidiocidal (kills) a. coopidol b. cycostat c. monensin d. salinomycin e. amprolium

Coccidia of Turkeys • Eimeria adenoides – lower SI and LI most pathognenic bloody droppings and mortality of up to 100% • E. gallopavovis – lower SI, ceca, rectum

•

E. meleagritis – 1-90% mortality; bloody diarrhea; necrotic entritis

Geese and ducks • Eimeria truncata – kidney, very pathogenic to gooseling; may cause 100% mortality • E. anseris – SI moderately pathogenic

2. all-in, all-out system of management – through cleaning 3. 4. 5.

and disinfection in between batches (at least 2 weeks vacant) elevated waterers, raise birds on-slated floor/wire in cases where drug resistance occur change coccidiostats. Regular switching of coccidiostats frequent removal of litter if possible

Pigeon • Eimeria columbae – SI non-pathogenic

•

E. lasseana – SI pathogenic to squabs o Blood tinged diarrhead

•

E. tropicalis – pathogenic to squabs

Coccidia of ducks 1. Eimeria anatis 2. E. bocchadis – kidney 3. E. matthae - ballooning of SI; hemorrhagic enteritis of 2-3 week old ducklings 4. E. saitame

Causes of ballooning of Small Intestine – hemorrhagic enteritis of ducklings 2-3 weeks of age Cyptosporidium sp. – oocysts produced on mucosa or surface epithelium of digestive and respiratory tracts causing respiratory symptom emerging disease of and high mortality can be mistaken for chronic respiratory disease (CRD), coryza, etc. Cryptosporidium tyzzeri – chicken cecum (extracellularly or the microvilli) Cryptosporidium melagridis – turkey, diarrhea and some mortality Wenyonella anatis – ducks Wenyonella philiplevinei – ducks Wenyonella gallinae – chickens Tyzzeria perniciosa – ducks S.I. Tyzzeria anseris – Geese S.I.

FAMILY SARCOCYSTIDAE Reproduction occurs in two hosts. Part of the subclass coccidian intermediate and final hosts are vertebrae • Intermediate Host – asexual reproduction takes place • Final Host – sexual reproduction takes place • Oocysts are reduced A. Asexual reproduction occurs in a variety of vertebrate I.H multiply by a. Binary fission b. Endocyogeny c. Endoplygeny d. Pseudocysts/cyst formation B. Sexual reproduction occurs in another vertebrate host which is the primary or final host • Schizogony and gametogony – syngamy --- oocysts formation occur in the intestinal tract usually of carnivores (Dogs, cats, etc.) • Genera a. Toxoplasma b. Sarcocystis c. Besnoitia d. Hammondia e. Frenkelia

GENUS Toxoplasma •

Cyst not septate/lobulated

•

Toxoplasma gondii – intracellular parasite of many types of tissue cells = endothelial, parenchymal, epithelial, muscular, blood and other cells of almost all animals including man (zoonotic).

Morphology: Occurs in 3 forms: 1. Trophozoite – banana shaped, reproduced by binary fission, endodyogeny and endopolygeny in tissue cells of various vertebrate IH. These are also known as tachyzoites, the rapidly multiplying forms 2. Pseudocysts or cyst – contains many zoites or bradyzoites (slow multiplying form) – found in the brain, lungs, liver and other organs of vertebrae I.H.

3.

Oocysts – produced after schizogony, gametogony and syngamy in the intestinal epithelium of cats and other animals of the feline family only (which are the F.H.) sporulation takes place in the ground. Sporulated oocyst has two sporocysts, each with 4 sporozoites (similar to Isospora)

Life cycle: When other trophozoites (tachyzoites) pseudocysts (bradyzoites) or sporulated oocyts (sporozoites) are ingested by cats (F.H.). the zoites invade the epithelial cells of the small intestine and undergo schizogony and gametogony oocysts is voided out with the feces and sporogony occurs in the ground in 3-4 days. The cycle is repeated when the sporulated oocysts are again ingested by cats. If animals other than the cat family like cattle, goat, pig, dog, man, etc. which serve as initial hosts ingest the zoites (spurozoited, tachyzoites and bradyzoites) the organisms invade tissue cells of various organs brain, spinal cord, liver, lungs, spleen, lymph node etc. where they multiply asexually by binary fission, endodyogeny or endopolygeny or form pseudocyst where they produce various clinical signs. Prepatent period 1. 3-5 days if tachyzoites an bradyzoites are ingested Transmission and Mode of Infection 1. congenital – transplacental 2. ingestion of infective materials Bradyzoites, Sporozoites)

2.

20-25 days if sporozoites are ingested a.

(Trophozoites, b.

infected meat, organ or whole (rodents/birds) cat feces with sporulated oocysts

animal

c. d. e. f.

venereal – coitus lactation – milk blood transfusion organ transplant

Pathogenesis 1. Asymptomatic in most cases

g. h.

2.

handling hand, gloves on vet exam secretions and excretions – nasal discharges, saliva

organisms invade fetus causing abortion and stillbirth

Clinical Manifestation: depends on organs affected, infection may be direct or indirect Life Cycle of Toxoplasma gondii 1. Attacks the central nervous system causing encephalitis, incoordination, paralysis, blindness and concunctivitis 2. lymphadenitis 3. fetal abnormalities – hydrocephalus and ascites, undeveloped eyes incomplete lens etc.

4. 5.

pneumonitis due to destruction of lung tissues acute form – fever, anorexia, jaundice, tremor in pigs, asymptomatic form in 20% (serologically).

Acute forms – similar to hog cholera, petechial hemorrhages on the skin, high fever, weakness of hindlegs, anorexia, conjunctivitis

Diagnosis: 1. Serological tests • Skin test

•

IHAT (Indirect Hemagglutination – Agglutination Test)

• •

CFT (Compliment Fixation Test) IFAT (Indirect Fluorescent Antibody Test)

2.

demonstration of organisms in tissue smears, impression, blood smears

Treatment: 1. Pyrimethamine 2. Sulfamonomethoxine 3. sulfamonomethoxine plus pyrimethamine combination Prevention: 1. Thorough cooking of meat Note: Not all cats carry T. gondii

2.

mouse inoculation/passages

4. • 5.

sulfadiazine pyrimethamine reduces oocysts output clindamycin (Antibiotic)

cats should not be fed raw meat

Genus Sarcocystis General Characteristics 1. Zoites are elongate 2. cysts are septate, filled with spores or rainey’s corpuscles or bradyzoites 3. both IH and FH are vertebrate animals 4. cyst (Sarcocyst, Miescher’s tube) found in the muscle of vertebrate IH

Species: • Sarcocystis fusiformis F.H. – dogs and cat I. H. – carabaos (cattle) • Sarcocystis cruzi F.H. – Dogs I.H. – Carabao, cattle • Sarcocystis bovicanis F.H. – Dog I.H. – cattle • Sarcocystis levinet F.H. – dog I.H. – Carabao, cattle

3.

• •

•

5. 6. 7.

3.

strict sanitation

4.

control of rodents

cysts are microscopic to macroscopic in size sporulated oocyst/sporocysts produced in the intestinal wall of vertebrate F.H. (carnivores: dogs and cats/man voided out with the feces high incidence in the Philippines

Sarcocystis tenella F.H. – cat F.I. – sheep, goats Sarcocystis ovicanis F.H. –dog I.H. - sheep S. hominis or bovi hominis F.H. – man I.H. – cattle

• • • •

S. bertrami F.H. – dog I.H. - equines S. miescheriana F.H. – dog I.H - pig Sarcocystis porcifelis F.H. – cat I.H. - pig Sarcocystis muris F.H. – cat I.H. – rats

Life Cycle: Sporulated oocysts which are voided out with the feces or F.H., contains 2 sporocyst, each with 4 sporozoites. Oocyst wall is delicate, usually ruptures and sprorocysts are also seen in fresh feces. If sporulated oocysts/sporocyts containing sporozoites are ingested by suitable F.H. the sporozoites are released in the small intestine and undergo gametogony (no schizogony and syngany). Oocyts are formed and sporulate in the epithelium of the small intestine of dog, cat, man etc. Prepatent period is 1-3 weeks. If infective materials (Sarcocyst, sporulated oocyst) are ingested by the I-I-, the zoites invade many tissues and undergo schizogony in endothelial cells of blood vessels in most organs. The resulting merozoites migrate to the muscles via the blood stream where they grow and form cyst or sarcocyst. Inside the sarcocyst, the spores (Bradyzoites) reproduce by binary fission or by endocyogeny.

Transmission or mode of infection: Ingestion of sporulated oocyst, sporocysts containing sporozoites or meat with sarcocyst (containing spores or bradyzoites) Symptoms: 1. Asymptomatic in most cases a. In acute cases – reduced milk yield 2. severe infection – muscular weakness, extreme submuscular emaciation, submuscular edema, toxin = sarcocystin fever Diagnosis: 1. finding sarcocyst in the muscle tissue (macro and micro) in carabaos may reach an inch long 2. finding trophozoites/spores in ground muscle

3. 4. 5.

abortion anemia, diarrhea, loss of weight death in severe infection

3.

finding sporulated oocyst/sporocyst in the feces of carnivores

Treatment: None Prevention: Dogs and cats should not be given raw meat since they serve as F.H. and dissimilar or sporulated oocyst /sporocyst in nature Genus Besnoitia Forms: 1. tachyzoites in tissues of I.H. 2. oocyst in connective tissue of I.H.

3.

Oocyst in interior tract of carnivores (F.H.)

Besnoitia besnoiti F.H. – rats I.H. – cattle Clinical signs • thickened and wrinkled skin • • hairs fall off like in mange • but without pruritus

emaciation some mortality below 10%

Transmission: 1. Ingestion of trophozoites and cyst with bradyzoites from tissues 2. ingestion of sporulates oocyst from the ground Besnoitia benetti – equine I.H. Genus Hammondia Hammondia hammondi

• • •

abortion sterility in bull acute fever – anorexia

• • •

edema, diarrhea enlarged lymph nodes rapid respiration

F.H. – Cats I.H. – rodents • Cyst in skeletal muscles, brain • Tachyzoites multiply in lamina propria of intestine and muscle Genus Frenkelia Frenkelia microti – I.H. – mice, wolves • Cyst in brain and spinal cord

ORDER HAEMOSPORIDIA FAMILY PLASMODIDAE Reproduction takes place in two hosts: schizogony (asexual) and gametogony occur in vertebrate host (secondary) while syngamy (sexual) and sporogony take place in invertebrate host (Final or Primary host) Genera: 1. Plasmodium

2.

Haemoproteus

3.

Leucocytozoon

Genus Plasmodium Schizogony occurs in the RBC and endothelial cells of solid organs (bone marrow, liver, lungs, etc. of vertebrate host syngamy and sporogony occur in mosquito vectors pigment granules (hemozoin) present. I. Avian Plasmodia • Plasmodium gallinaceum chickens • P. juxtanucleare – chickens

• • • •

–

P. relictum – pigeon P. durae – turkey P. lophorae – pheasant P. elongatum – sparrow, canaries

Mosquito Vectors (Primary/Final Host) I. Avian forms – culicine mosquitoes a. Culex spp. b. Aedes spp.

• II. • • • •

P. cathemerium - sparrow Human Plasmodia Plasmodium ovale P. palciparum P. malariae P. vivax

III. Rodent malaria • Plasmodium berghei

• IV. • • • • • •

P. vinckei Simian malaria Plasmodium knowlesi P. cynomolgi P. brazilianum P. kochi P. inui P. simium

II. Mammalian forms – human, simian, rodent a. Anopheles mosquitoes – Anopheles spp.

Life cycle of Avian Plasmodia Sprozoites are inoculated by culicine mosquitoes. Enters macrophages and fibroblast of the skin – from first generation preerythrocytic schizont called cryptozoite. Merozoites from the latter, envades other macrophages – form the second generation preerythrocytic schizonts – the metacryptozoites. Merozoites from metacyptozoites enter erythrocytes and other cells of the body and form erythrocytic and exoerythrocytic schizonts respectively. Merozoites from erythrocytic schizonts invade other RBC and either repeat schizogonic process or proceed to gametogony forming micro- and macrogametocytes. (some erthrocytic merozoites invade endothelial cells and produce exoerythrocytic schizonts, the phanerozoites). Merozoites from exoerythrocytic schitionts invade RBC and initiate further erythrocytic schizogony . Macrogametocytes and microgametocytes are ingested by culicine mosquitoes and in the gut, macrogametocyte matures into one macrogamete while microgametocyte matures and a number of microgametes (6-8 flagella-like) are formed and extended out from the parent cell by exflagellation process. Once macrogamete is fertilized by a single microgamete (syngamy) forming a motile zygote, the ookinete. The ookinete penetrates themidgut wall and lie on the other surface of the stomach, forming oocyst sporogeny then takes place forming several sporozoites. Oocyst ruptures and sporozoites are released, migrate to the salivary gland – proboscis and finally transmitted to birds when the mosquito bites to suck blood. Mosquitoes are infected throughout the entire life span.

P. gallinaceum – occurs in chickens endemic in India, Pakistan and other neighboring countries not a problem in the Philippines. Vectors are Culex and Aedes mosquitoes causes a disease condition known as “Avian malaria gallinaceum”. Gametocystes are big, round or irregular with pigment granules. Schizonts in RBC round to irregular in shape; 6-30 merozoites. Displaces host cell nucleus. Host cell distorted The Lifecycle of Plasmodium sp. (Malaria)

Pathogenesis and Clinical signs Mortality up to 80% or more in endemic areas. Progressive weakness, emaciation, severe anemia, greenish diarrhea and sometimes paralysis due to massive number of the parasite in endothelial cells of the brain Up top 90% of the RBC may be parasitized Pathology • spleen and liver are enlarged

•

pale muscle and mucous membrane

Plasmodium juctanucleare – chickens (wild and domestic) • prevalent in P.I. • causes “Avian malaria juxtanucleare”

•

vectors – Culex sp.

Gametocytes are usually elongate – pyriform, may be round; schizonts small with 3-7 merozoites, usually in contact with the are nucleus. Host cell not distorted, nucleus not displaced. Parasitemia usually low – 3-5% or less. Rarely higher Symptoms: Anemia and emaciation Low Mortality Diagnosis: Blood smear and examination and finding schizonts and gametocytes in RBC Treatment: • Paludrine 7.5 MG/KGM • Chloroquin – 5 MG/KGM • Plasmochin – 5MG/KGM

• •

Sulfamonomethoxine – pyrimethamine combination Trimethroprim S.Q. combination

Human malaria – characterized by paroxisimal attack – chilling, fever and sweating Paroxysm – is due to release of toxin upon periodic rupture of mature schizonts. Plsmodium palciparum “malignant malaria” - most common form of human malaria widely distributed in the tropics.

Quotidian malaria – schizognic cycle takes one day. Paroxism occurs in day 2.

Tertian malaria – schizogomic cycle takes two days. Paroxism occurs in day 3. Quartan malaria – schizogonic cycle takes three days. Paroxism occurs in day 4.

Plasmodium malariae – quartan malaria - less common in tropical and subtropical Plasmodium ovale – mild tertian malaria - Philippines, India, Africa Plasmodium vivax – “benign tertian malaria” - most common and widely distributed

Genus Haemoproteus Schizogony in endothelial cells of blood vessels especially the lungs and not in RBC. (no erythrocyctic schizogony) only gametocytes occur in RBC. Found in blood sucking insects Hippoboscid flies and Culicoides sp of some cases. Pigment granules present in gametocytes. Host cell not usually distorted. H. columbae in pigeons causing “pigeon malaria” prevalent in the Philippines. Also affect doves and wild birds. Only sausage shape gametocytes are found in RBC. Pigment granules present. Most cells usually not distorted. Vectors are pigeon louse fly – Pseudolynchia (maura) canariensis Life cycle: Sporozoites introduced by pigeon lousefly either repeat schizogony or undergo gametogony ookinete oocyst sporozoites proboscis.

endothelial cells of blood vessels schizonts cytomeres merozoites gametocytes in RBC (micro and macro) syngamy zygote

Pathogenesis Many pigeons harbor the organism without showing signs. Heavy mortality may occur among squabs. Frequent signs are anemia and emaciation, on post-mortem, liver and spleen are enlarged.

Control Diagnosis is by blood examination and finding of gametocytes in RBC Treatment no satisfactory treatment quinacrine may affect gametocytes but not schizonts Prevention – control of pigeon lousefly sp (Psuedolynchia maura and canariensis) Other species: Haemoproteus meleagridis – turkey; gametocytes – sausage shape. Vector – unknown H. nettionis – ducks and geese; gametocytes – susage shape. Vector – Culicoides sp H. sacharovi – pigeons and doves; gametocytes – irregular or round. Vector – Pseudolynchia sp and Culicoides sp.

GENUS Leucocytozoon Schizogony in endothelial and parenchymal cells of liver, lungs, spleen, testes, ovary, intestine etc. gametocytes in erythocytes or leukocytes. Depending on the species. Pigment granules absent. Syngamy and sporogony in blood sucking insects. Disease condition – leucocytozoonosis Leucocytozoon cauleeryi – the cause of chicken leucocytozoonosis Vectors – are biting midges Culicoides sp. Gametocytes are found in RBC which some enlarged, distorted and damaged. Most prevalent blood parasite of chickens in the Philippines also present in many countries of the far-east Japan, Burma, Taiwan, Malaya, Thailand etc.

Life cycle: basically the same as H. columbae except that: 1. schizogony occurs on the endothelia and parenchymal cells of solid organs – liver, lungs, spleen, testes, ovary, intestine etc. 2. gametocytes – are round and RBC are distorted and destroyed

3. primary host are Culicoides sp 4. secondary host are chicken 5. self limiting – after one developmental cycle, the chicken becomes free of parasite and recover.

Leucocytozoon simondi·Fig. 1. Life cycle of Leucocytozoon simondi in its vertebrate hosts (domestic and wild ducks and geese) and in its vector ( spp., black flies). 1–5 Sporozoites injected by the Simulium fly are carried by the bloodstream to the liver, where they enter Kupffer cells and form the multinucleate first-generation schizonts. The latter give rise to small merozoites (5) which may reinfect other hepatic cells (2) or invade lymphoid cells (6–8) or erythrocytes (9.1). 6–8 After invasion of lymphoid cells or macrophages 4–6 days after infection, large schizonts (= megaloschizonts) of 60–150 μm diameter are formed, which via cytomeres (7) produce numerous merozoites (8). 9–12 Having entered lymphoid cells, the majority of merozoites probably develops into gamonts (9.2), but it is thought that some may initiate further asexual reproduction. During the formation of the finally elongate or ovoid (20 × 5 μm) the host cells become distorted and appear elongated-spindle-shaped (10.2). Occasionally, spherical gamonts appear (10.1) which are thought to originate from hepatic merozoites (5) that have penetrated erythrocytes instead of lymphoid cells. However, there is no evidence that these differ functionally from the elongate forms. When the vector has sucked blood, the formation of (11, 12) is initiated inside the gut, leading, after fertilization, to an extracellular 13–17 The immobile zygote is transformed into a motile , which enters the intestinal wall (15), migrates through the of a gut cell and begins its transformation into an situated between basal membrane and epithelial cells of the gut (17). 18–20 Formation of multinucleate sporoblasts (18) which give rise to numerous sporozoites (19; SP). The latter are released into the body cavity and migrate to the salivary glands (20). These slender sporozoites are finally injected into the next host. CY, ; DG, developing microgamete; E, erythrocyte; HC, host cell; IE, intestinal epithelium; L, lymphoid cell/macrophage; N, nucleus; NH, nucleus of host cell; PV, SG, SP,

Symptoms: – anemia, hemoptysis – depressions, dullness – weakness

– – –

greenish diarrhea ruffled feathers poor apetite

Pathology: 1. liver and spleen enlarged 2. gall bladder suspended with bile 3. hemorrhagic spots (petechiae) in the combs, liver, muscles and other organs, may be absent. Diagnosis: 1. blood examination

2. ring forms

– –

morbidity 30-50% mortality 0-20%

4. blood clot maybe present in the abdominal cavity 5. muscle very pale

3. mature gametocytes

Treatment and Prevention 1. sulfa monomethoxine sodium feeds 20-25, treatment 1 gram/litter prophylactic 1 gram/20litters continuously 2. sulfamonomethoxine 15ppm. Pyremethanine 3ppm 3. clopidol 66ppm L. sabrazesi- chickens mature gametocytes in spindle shaped WBC.

4. developing gametocytes

4. halofuginone 4-5ppm 5. control of Culicoides sp. – breeding places, larvicides, good drainage

L. simondi- ducks and geese causing “duck and geese malaria” in the U.S, Canada, Europe. Mature gametocytes in spindle-shaped WBC. Vectors are Similium sp. Or black flies. Gametocytes persistently present in the blood circulation. L. simondi is markedly pathogenic to young ducks and geese death. Mortality is usually 30-50% but may reach up to 100% Diagnosis: blood smear examination and finding spindle-shaped host cell with gametocytes Treatment: Clopidol in feeds Prevention: 1. control of Simuliun sp. 2. raise duckling away from carrier adults. L. smithi turkeys caused “turkey malaria” or turkey leucocytozoonosis in US gametocytes in elongated spindle shaped WBC Vectors – Simulium spp Pathogenesis: Strongly pathogenic to young turkeys. Mortality may reach up to 90% Clinical signs: Anorexia, emaciation, leg weakness, incoordination Diagnosis: blood smear examination and finding gametocytes Treatment: 1. sulfaquinoxaline (treatment) 2. clopidol (prevention) 3. control of black flies

FAMILY BABESIIDAE Babesia or piroplasma – piroplasmosis or babesiosis (a disease primarily of older animals) pyriform, amoeboid intracellular, multiply in the RBC into two or more nonpigmented pearshaped organisms. Lie charactistically at an angle with narrow ends in apposition. Babesia are divided into two groups: I. large forms – more than 3u II. small forms – less than 3u Life cycle in general: In the vertebrate host, multiplication occurs in the erythrocytes by budding, binary fission or multiple fission forming 2, 4 or more trophozoites. These are liberated and invade new RBC until large number are readily transmitted mechanically by blood inoculation. Under natural condition and transmission of Babesia in ticks is either transovarian or transtadial (stage to stage)

Life cycle of Babesia spp. in the tick and vertebrate hosts. Events in the tick begin with the parasites still visible in consumed erythrocytes. Some are beginning to develop Strahlenkörper forms (A). The released gametes begin to fuse (note that only one of the proposed mechanisms is pictured; one gamete has a Strahlenkörper form, whereas the other does not) (B). The formed zygote then goes on to infect and move through other tissues within the tick (C) to the salivary glands. Once a parasite has infected the salivary acini, a multinucleate but undifferentiated sporoblast is formed (D). After the tick begins to feed, the specialized organelles of the future sporozoites form (E). Finally, mature sporozoites bud off of the sporoblast (F). As the tick feeds on a vertebrate host, these sporozoites are inoculated into the host (G). Not shown is the preerythrocytic phase seen in Theileria spp. and T. equi (B. equi). Sporozoites (or merozoites) contact a host erythrocytic and begin the process of infection by invagination (H). The parasites become trophozoites and can divide by binary fission within the host erythrocyte, creating the various ring forms and crosses seen on stained blood smears (I). Illustrations are not to scale.

Transovarian transmission – adult female ticks takes infected RBC. The parasite enters the developing tick egg and is transmitted by larvae, nymphs and adults of the next generation. This is the mode of transmission in one host ticks. Example: Babesia bigemina and Babesia microplus Development does not occur unless ticks are replete with blood otherwise the organism dies or retarted. In the tick gut epithelium, the parasites undergo multiplication process similar to schizogony producing “fission bodies” (schizonts) containing club-shaped forms called “vermicules” similar to merozoites. Mature fission bodies rupture and the vermicules are released into the gut lumen. Vermicules penetrate the gut wall into the hemonymph to enter the ovary and finally the developing eggs. When the egg hatches into larvae, the organism undergoes multiplication (schizogony) in the gut epithelium. Vermicles enter salivary gland when the larvae molts into nymph, the vermicules invade the salivary glands where large schizonts are again formed producing infective vermicules. Transtadial transmission or stage to stage – Babesis ingested into larval or nymphal ticks is transmitted by the succeeding stage (nymph or adult) occurs in 2 or 5 host ticks. Example: B. canis in R. sanguineus Phagocytes just beneath the hypodermis in the body cavity undergoes schizogony forms containing club shaped forms (vermicules) club shaped forms are liberated and invade the tick. Muscle cells divide into large number of small ovoid forms. When adult emerges from the nymph and feeds the organism migrate to the salivary glands and further reproduce by repeated binary fission into large number of small ovoid infective dorms. Schizogony occurs in the salivary glands of nymph and adults but most transmission is by adults. Babesia of cattle Babasia bigemina B. bovis – Argentina B. divergens B. bigemina - CATTLE 1. Worldwide in distribution in the tropics and subtropics. 5. Pyriform in pairs, round, oval, Irregular 2. Philippines 6. Vectors are principally Boophilus sp. 3. Morphology: large piroplasm (2X4-50) 7. Intra-Uterine transmission possible 4. Round forms are 2-3U in diameter PATHOGENESIS: Causes disease known as “Texas Fever”, Red water, Cattle tick fever, Bovine Malaria or piroplasmosis, Bovine Babesiosis. CLINICAL SIGNS: 1. Calves below 1yr. are resistant, frequently asymptomatic. 2. Incubation period 1-2 weeks. 3. 1st. sign-high fever(106-1080F OR 41-420C) severe anemia develops up to 75% or RBC being destroyed, mucous membrane becomes pale , ecteric and increase in heart and respiratory rates. 4. Hemoglobinuria-usually present (coffee-colored urine) 5. Initially- Profuse diarrhea followed by marked constipation, anorexia, depression, weakness, cessation or rumination and drop in milk yield.

6. 7.

8.

Mortality- As high as 30-90% in untreated outbreaks. Death occurring within a week onset. Animals that survive acute phase go into chronic phase for several weeks duration. Characteristics intermittent fever(40-40.5%) emaciation, diarrhea or constipation but usually without marked hemoglobinuria. Cerebral form is characterize by sudden onset high fever, incoordination followed by posterior paralysis or convulsions, coma and death.

POST MORTEM: Anemia, Icterus, Subcutaneous and intramuscular edema splenomegaly (maybe 6 times the normal size), Hepatomegaly distended gall bladder with thick dark blue bile,red urine or dark brown in color. IMMUNOLOGY:

1.

2.

Their is inverse age resistant . Calves resistance. Asymptomatic and have very low parasitemia. Adults very susceptible. Clinical signs marked. Accquired immunity a premunition. Immunity to reinfection is due to continuing low grade infection. Life long immunity for B. bigemina but may be overcome by

3.

DIAGNOSIS: 1. Clinical signs- high fever, anemia and hemoglobinuria are suggestive of babesiosis. 2. Demonstration of organism in the peripheral blood smear especially during period of high fever.

3.

4.

B. bovis Argentina cattle of temperate countries present in the Philippines (small piroplasm (2.4-1.5u) sygnet ring forms particularly common. Also pyriform or irregular. vectors: Ixodes sp. Boophilus sp.Rhicephalus spp. Disease similar to but more severe than B. bigemina premunition does not last 2 years.

stress (parturition,starvation etc.) if the parasite disappears the animal becomes fully susceptible again. Spleen plays important role in maintaining immune status. Splenectomy is often followed by severe or fatal released in the “premunized animals. Splenectomized animals are also more susceptible to infection and much more seriously affected. Animal inoculation 50-100ml of suspected blood I.V. or SC to splenomectomized calves. SEROLOGICAL HEMAGLUTINATION I-F-A-T

B. divergens-cattle of N. Europe. Smallest Bebasia sp. Of cattle (1.5X.40). Usually paired and widely diverged lying superficially in RBC. vectors: Ixodes ricinus

DIAGNOSIS: - Smears from heart, kidney, brain, and peripheral blood obtained from tail tip. CLINICAL SIGNS 1. Babesia of sheep and goats

2. B.motasi-in Europe, Asia and America

SIGNIFICANT SIGNS: Fever, anemia, Haemaglobinimia Babesia of Horses, Donkeys, Mules Babesia caballi, B. Equi Babesia caballi Resembles B.begemina 2.5-4u longs. Vectors: Dermacentor spp. Rhicephalus spp. and Hyalomma spp. Pathogenesis: 1. Anemia icterus but Hemaglobinuria is rare and not characteristic. 2. Paralysis common.

3. Inverted age resistance. Recoverd horses are premune for 1 to 2 years.

DIAGNOSIS Clinical signs 1. Demonstration of organisms 2. Serological test Compliment Fixation Test, Flourescent Antibody Test B. equi Morphology:smaller than B. caballi 2u long and characteristically divides into 4 daughter cells which frequently form a “maltese” cross appearance. Vectors: Dermacentor , Rhicephalus, Hyalomma spp Pathogenesis: More pathogenic than B. caballi. Significant signs are fever anemia, icterus, Hemoglobinuria and Edema. Paralysis (common in caballi) is not usually seen in B. equi. Mortality: 10-50% if not treated. BABESIA OF SWINE B. trautmanni, Europe, Africa, USSR B. peroncitoi- Sudan

BABESIA OF DOGS B. canis- dogs worldwide P.I B.gibsoni- dogs in S. Asia B.vogeli-dogs S. Asia Africa

Babesia canis – dogs worldwide common in the Philippines. 1. Large (4-55 Long)cytoplasm frequently vacuolated. Pleumorphic ring, ameboid, irregular forms. Multiple infection of RBC common up to 16 organism in a single RBC. V ectors: Rhicephalus spp. Principally Dermacentor spp., Haemaphysalis spp

PATHOGENESIS: 1. Causes “Biliary fever” or malignant jaundice. Puppy may show clinical disease more severe than in adults(unlike Babesiosis in other animals). 2. disease more severe in imported dogs Atypical cases 1. respiratory type – bronchitis, pneumonia. SC, edema, ascites 2. nervous type – dist, locomotion epileptiform. Fits paresis, coma

3. 4.

Incubation period 10-21 days. Typical signs are fever, depression, anorexia, jaundice, hemoglobinuria (sometimes) splenomegaly. Chronic intermittent fever anemia, weakness, emaciation.

3. 4.

gastrointestinal type – gastritis ocular type – keratitis, iritis

Immunity: recovered animals are pre-immune for life Diagnosis – demonstration of organism in capillary blood. At a time difficult to demonstrate. Clinical signs 1. animal inoculation – 10ml of blood to splenectomized dogs

2. B. gibsoni – produces more chronic disease than B. canis

3. B. vogeli similar to B. canis but no cross immunity

Babesia of cat Babesia felis – small (1.5 – 2u long) round, oval forms, divides into four: organism forming “maltese cross” arrangement. Important signs are anemia, icterus and emaciation Diagnosis – clinical signs, blood smear exam. Treatment of babesiosis – piroplasmosis treatment. Cattle: 1. trypan blue – 100ml of 1-2% solution I.V 2. acriflavine – 20ml of 5% solution I.V 3. ganaseg – 3mg/kgm 5% I.M (berenil) 4. pirevan – 1ml of 5%/50kgm SC (babesam/acaprin)

5. 6. 7. 8.

diampron – 10mg/kgm I.M or SC (amicarbilide) drug of choice for cattle imizol or imidocarb – 1mg/kgm SC or IM (imidazole) diampron – 5-10mg/kgm IM orSC dogs – ganaseg 3-10mg/kgm IM

Supportive treatment 1. blood transfusions 2. hemtinics Zoonotic Babesia Babesia bovis

Babesia microti

B. divergens

Prevention and control of babesiosis 1. tick control – regular dipping of cattle 2. prophylacyic medication a. imidocarb – 2mg/kgm SC protects cattle for 3 months 3. preimmuniztion a. inoculation of young calve below 6 months with mild strain of B. bigemina or B. argentina with 5ml blood from carrier cattle if clinical disease occur as a result of inoculation, treat with imidocard, ganaseg etc. Family Theileriidae Organism are round, ovoid, comma shaped, rod like ring or irregular form found in erythrocytes and lymphocytes of cattle, buffaloes, sheep and goats. Produce macro schizonts (agamont) and micro-schizonts (gamonts). Pigment granules absent. Transmitted by ticks, disease condition produced is called “theileriasis”. Not reported in Philippine Islands Species affecting cattle and buffaloes Theileria parva- east coast fever T. annuluta- tropical theileriosis T. mutans

T.lawrenci Theileria parva - causes east coast fever or bovine theileriasis in Africa, High mortality among susceptible imported stock. Primary host- ticks

Life cycle 1. Sporozoites are inoculated by ticks in vertebrate host.

2.

Schizonts are formed in the lymphocytes and endothelial cells.

Two forms of schizonts: 1. Macro-schizonts or agamont with large chromatin granule and form macromerozoites. Repeat the cycle until the majority of the lymphoid cells are paralyzed.

2. Micro schizonts or gamonts with smaller chromatin granules and product micromerozoites.

Micromerozoites attack RBC. (Mostly rod shaped). Infected RBC are ingested by ticks (especially R. appendiculatus) in the tick – ookinete—sporozoites are produced which are infective. Symptoms: higher fever. Up to 90% of RBC may be parasitized at the height of the fever. Dry hemorrhagic feces. Marked emotion, weakness. Enlarged superficial lymph nodes. Mortality up to 100% Post mortem: Enlarge spleen and liver. Petechial hemorrhages on serous membranes. Swollen lymph nodes. Transmission: Normally by ticks. Inoculation of emulsified spleen and lymph nodes (T.parva, is not transmissible by blood transfusion/inoculation. Diagnosis: 1. Clinical signs - Absence of anemia and icterus aid in differentiating “east coast fever” from piroplasmosis.

2. Demonstration of schizonts from the lymph nodes and spleen puncture (biopsy).

3. Demonstration of forms in RBC (sometimes difficult)

Treatment: chlortetracycline, Oxytetracycline, Halofuginone Prevention: control of ticks Recovered animals are immune to reinfection T. anulata- cattle and buffaloes T. mutans- cattle of Africa, Asia, Australia and Soviet Union causes “benign bovine Theleriasis” which is almost non-fatal. Transmitted by Rhipicephalus, Haemaphysalis and Boophilus spp. T. hirci-sheep and goat- 50-100% mortality

T. ovis-sheep and goat-benign theilerriosis Haematonexus veliferus- cattle Haematoxenus separatus-sheep Similar to theileria but RBC forms have rectangular veil extending from their sides.

Family Haemogregarinidae Genus Hepatozoon Schizogony in the endothelial cells of the liver. Gametocytes in the leucocytes and erythrocytes depending on the species. Hepatozoon canis- dog, cat (Present in the Philippines) Schizonts in the endothelial cells of the spleen, bone marrow and liver. Gamonts/gametocytes occurring in leucocytes forming rectangular bodies measuring 3x12 microns by 3-6 microns surrounded by delicate capsule, stain pale blue with reddish purple nucleus. Developmental cycle The dog is infected through ingestion of infected tick (R. sanguineus) which contains sporozoites in the body cavity. Sporozoites penetrate intestinal walls of dog. Spleen Liver bone marrow and become schizonts merozoites invade leucocytes become gametocytes/gamonts. Upon ingestion gametocytes leaves leucocytes in the alimentary canal of tick gamete male and female gametes unite (fertilization) zygote ookinete penetrate intestinal wall of tick haemocoele sporoblast sporocyst with sporozoites. On the ingestion of ticks oocyst and sporocyst are ruptured to release the sporozoites. Pathogenesis and clinical signs. May be asymptomatic Clinical signs- irregular fever, anemia, progressive emaciation with the enlargement of spleen, Lumbar paralysis may occur. Diagnosis: demonstration of gametocyte in stained blood smear or schizonts in spleen and bone marrow. Treatment: no known effective treatment but tetracycline and imidocarbs give best results. Hepatozoon muris - Brown rats (Rattus norvegicus) Hepatozoon musculi - mouse Hepatozoon cuniculi - rabbit Genus Anaplasma, Eperythozoon, Haemabartonella, Aegyptianella, Grakamella, Ehrlichia

1. Anaplasma marginale et centrale Host- cattle Disease- anaplasmosis or gallstickness Morphology: small spherical bodies, red to dark red in the color found in the RBC. Transmission- mechanical tick, Tabanids, Stableflies, mosquitoes, dehorning, mass vaccination or castration. Symptoms: fever, anorexia, weakness recumbency, dehydration. Loss of weight, pale mucous membrane (anemia). Marked icterus. Slow labored breathing, constipation. Parasitemia 30-50%. Mortality usually 10% but may reach as high as 80%. Post mortem: watery blood, distended gall bladder, enlarged liver. Diagnosis: anaplasmosis should be suspected when there is: 1. Icterus and anemia without Hemoglobinuria 2. Demonstration of organism in the RBC. 3. Thin and watery blood.

4. Distended gal bladder and enlarged liver and spleen on post mortem.

Treatment: 1. Tetracyclines injection 2. Imodocarb injections with supportive treatment either- blood transfusion, dextrose administration, I.V large amount of water through s. tube mild laxative. Avoid rough handling. Prevention: 1. Control of ticks and blood sucking flies 2. Proper precaution in surgical operations 3. Antibiotic administration with the feed at 2-3 weeks interval in the enzootic areas. Eperythrozoon suis- pig E. parvum-pig

4. preimunization- 5ml. of blood from cattle. Eperythrozoon Minute ring or coccoid shaped granular bodies in the RBC.

E. wenyoni-cattle E. ovis- sheep

May produce anemia and jaundice “icteroanemia” or “yellow belly” in pigs- Eperythrozoon suis is not pathogenic. May cause high morbidity in suckling pigs. Treatment: tetracyclines injections Haemobartonella - round, oval bodies of the RBC ,or coccoid forms in chain Haemobartonella felis- cats-“feline infectious anemia” H. canis- dogs − causes haemobartonellosis − Causes progressive anemia and emaciation, jaundice Diagnosis: identification of organism in the RBC. Treatment: 1. blood transfusion

2.

Tetracycline

3.

Ehrlichia- cause of Ehrlichiosis Coccoid, introcytoplasmic forms in the WBC. Transmitted by ticks Ehrlichia bovis E. ovina

Chloramphenicol

4.

E. canis

E. equi

E. canis- causes “tropical canine pancytopenia” or thrombocytopenia Class Ciliata- the ciliates Cilia for locomotion. Has 2 nucleus –macronucleus -micronucleus Reproduction- transverse binary fission (asexual) and conjugation (sexual) Genus Balantidium

Thiacetarsamide (caparsolate)

Balantidium coli- causes “balantidial dysentery”. In pigs and man. Most prevalent protozoon parasite in swine macronucleus is beanshaped. Micronucleus lies in a notch of macronucleus body covered with cilia. Cyst are ovoid or spherical. Transmission: ingestion of cyst Pathogenesis: causes mild to severe enteritis resulting to watery diarrhea and dehydration and dehydration particularly among the weanling pigs. May cause superficial or deep ulceration of the intestines. Diagnosis: fecal examination and finding of vegetative motile Trophozoites and cysts. Treatment: not easy to treat. Tetracycline per os. Tetracycline plus carbasone per os, sulfonamides. Prevention: good management and sanitation, thorough disinfection of pig pens with boiling water or 10% formalin. Species of uncertain classification Pneumocystis carinii - causes interstitial pneumonia in man and animals in very young and old especially with debiletative factors such as AIDS. Association of protozoa and fungi commonly seen in animals infected with immunosuppressive drugs.