Diseases Of Lab Animals

Mice DNA Viral Infections Non-enveloped Adenovirus

DDX: Replicate in nucelus; INIB

Macrophage, endothelial cells, adrenal cortex, renal tubule, thymus

Hemorrhagic encephalitis in susceptible mice; Hemorrhagic enteritis, fatty liver, wasting disease

Enterotropic

runting

thymic involution, necrosis of liver and spleen

Mouse Adenovirus-1

Murine adenovirus A

Polyomavirus, cytomegalovirus

Mouse Adenovirus-2

Murine adenovirus B

Mouse Cytomegalovirus

Murid Herpesviris -1

Replicate in nucleus and cause cytomegalic inclusions with INIB and ICIB

salivary glands

Mouse Thymic Virus (MTLV)

Murid Herpesvirus -3

INIB

Thymus

Thymic necrosis, granuloma

INIB

Salivary gland tumors, kidneys, 40 other cell types

Multifocal necrosis and inflammation

Tumors of mammary gland, salivary gland, thymus, skin tumors, renal sarcoma, osteosarcoma, hemangiosarcoma, fibrosarcoma

DDX: Mouse hepatitis, Pneumocystis, Sendai, Pneumonia virus of mice, adneovirus, cytomegalovirus

INIB in vascular endothelium

replicates in intestinal capillary endothelium

liver, lung, brain, spleen

pulmonary vascular edema and hemorrhage

DDX: Polyoma virus of mouse, adenovirus, cytomegalovirus

INIB in spleen mononuclear cells

Kidney, intestine, lymphoid tissue, liver

hemorrhage, hematopoietic involution, renal papillary infarction

more pathogenic for hemopoietic tissue than MPV; Targets outer granular layer of cerebellum

ICIB, basophilic to eosinophilic especially hepatocytes

Direct contact through cutaneous trauma; readily infects placenta and fetus

spleen, liver, kidney, lung, intestine; amputating lesions, intestinal hemorrhage, necrosis

necrotizing hepatitis, lymphocytic meningitis

zoonotic

Intestinal epithelial are unique to Madv-2

Enveloped Herpesvirus Betaherpes Eosinophilic INIB, ICIB, in Does not cross the placenta, may cause salivary glands, fetal death and resorption, delayed birth, ;lymphoplasmacytic infiltration runts of the interstitium, focal necrosis

DDX for sialoadenitis w/ Inclusions: Polyomavirus, (no inclusions=Reovirus 3, Mouse thymic virus, Mammary tumor virus) DDX: Coronavirus or stress

Polyomaviridae

Murine Polyomavirus

K-Virus

Murine pneumotropic virus (MPtV

Parvoviridae Mice Minute Virus (MVM)

Mouse Parvovirus 1

similar to MVM, but infects mice of all ages

Ectromelia

Ectromelia virus (ECTV)

Poxviridae related- vaccinia, variola, monkeypox, cowpox

necrosis of spleen, liver, lymph DDX: Hepatitis, MHV, Tyzzers, Salmonella, bite wounds, node, peyer's patches, thymus alopecia, hypersensitivity, gangrene

MousePox

RNA Virus

Arenavirus

Arterivirus

runts, wasting, vasculitis, Lymphocytic Choriomeningitis glomerulonephritis, Virus lymphocytic infiltration in brain , liver, adrenal, kidney, lung Lactate DehydrogenaseElevating Virus Infection (LDV)

Necrosis of T cell in lymhpoid tissue, generalized splenomegaly, lymphadenomegaly

Scattered neuronolysis with apoptosis and perivasculitis, non-suppurative leptomeningitis, myelitis, radiculitis

Coronavirus

hepatic nodular hyperplasia with necrosis and syncytia of parenchyma parenchymal collapse and endothelial cells- liver spleen, red Murine Hepatitis Virus (MHV) and fibrosis, splenic and white pulp, GALT, thymys and bone necrosis, Neurologic, marrow vestibular, paresis in immunodeficient mice

Pneumonia virus of mice (PVM)

Mild necrotizing rhinitis, Alveolar septae are thickened with necrotizing edema and macrophages and bronchiolitis, nonleukocytes, and alveolar spaces are suppurative interstitial Murine pneumovirus (MPV) collapsed and filled with fibrin, blood and pneumonia with macrophages and large polygonal neutrophils, mononuclear cells (detached Type II lymphocytes and pneumocytes) macrophages

DDX: Lymphoproliferative disorders, amyloidosis, glomerulonephritis, Chronic renal disease

DDX: Mouse encephalomyelitis virus (MEV), MHV, or retrovirus

enterotropic MHV- depends on ageneonates have villous attenuation, syncytia, and mucosal necrosis

Residual brain lesionsDDX: adults- Salmonella, Tyzzers, Mousepox; Neonatesperivascular cuffing of Reovirus, Cytomegalovirus, adenovirus; Enteritis- epizootic lymphocytes and vacuolation/ diarrhea, salmonella, Tyzzers, Reovirus; Demyelinatinggranulomatous serositis in IFN Mouse encephalomyelitis virus, LDV, Polyoma virus in deficient mice immunodeficient mice

Paramyxoviridae

Sendai Virus

Picornaviridae

Sendai Virus (SeV)

Infects respiratory epithelium and Type II pneumocytes

CD-8 Triggered apoptosis of infected cells

DDX: Pulmonary disease and wasting- Sendai and Pneumocystis murinus (immunodeficient) PVM tends not to induce bronchiolar hypertrophy like Sendai virus

Segmental necrotizing airways with inflammation as well as foci of interstitial pneumonia

neutrophils, macrophages, lymphocytes, fibrin in alveoli, DDX: Mycoplasma, Corynebacterium kutscheri. Mild atelectasis; Bronchiolar lesions can look like PVM or MHV. Immunodeficient mice epithelium may be can look like PVM or Pneumocystis murina hyppertrophic and hyperplastic prior to apoptosis

MEV or Theilovirus (ThV); Mouse encephalomyelitis virus Mouse poliovirus or Theiler's virus

Viral encephalitis and demyelination

SCID mice have marked vacuolation and attacks neurons and glia; neuronolysis, enlargement of affected neurons, in the neuronophagia, microgliosis, nonbrain stem and ventral horn of a spinal suppurative meningitis and perivasculitis cord.

DDX: neurological disease- trauma, neoplasia, otitis, MHV, LDV; In immunodeficient mice polyoma virus

Reoviridae

Mammalian orhtoreovirus (MRV)

mouse reovirus

enters through Peyer's patches

neonatal disease

Runted, jaundiced, steatorrhea, dorsal alopecia

Rotavirus-A (RV-A)

Epizootic Diarrhea of Infant Mice (EDIM)

Infects terminally differentiated enterocytes of villi of small and large intestine

Loose mustard colored feces staining the perineum

Hydropic change and vacuolation of enterocytes at the tips of villi

Diffuse encephalitis with vascular distribution; Necrotizing myocarditis, necrosis of lymphoid tissue, necrotizing hepatitis, portal hepatitis, acinar pancreatitis, and sialodacryoadenitis

DDX: Neonatal disease with steatorrhea- mouse hepatitis virus, EDIM virus, Salmonella

DDX: Enterotropic MHV, MAdV, reovirus, Salmonellosis, Tyzzer's disease

Caliciviridae

Norovirus

Murine norovirus (MNV-1)

Non-pathogenic, tropism for Alveolitis, pulmonary edema, coagulation macrophages and necrosis in liver, minimal inflammation, Multiofcal mononuclear hepatitis, dendritic cells, replicate necrotizing splenitis, endothelial interstitial pneumonia, pleuritis, peritonitis in lung liver, and hypertrophy in STAT1 null mice lymphoid organs in macrophages

Retroviridae

general info

Other autonomous retroelement flanked MuLV and MMTV's by LTR's are: Intracisternal A particles Non-autonomous retroelements must borrow reverse encode their own (IAP's), MusD elements, VL30 elements, LINE's are long interspersed retroelements make up 37% of the mouse genome, most transriptase- they encode no proteins but are flanked by reverse transcriptase Most are methylated and glutathione tRNA primer binding sites nucleotide sequences and considered genetic parasites. These require transcription LTR's (early transposons (Etns), Short interspersed and are incorporated transcriptionally silent due to mutation (GLN's), and murine endogenous make up 20% of the genomefrom RNA to DNA- gag, pro, pol, env genes flanked by LTR's nuclear elements (SINES); Also there are numerous LTR's into the genome retroelements (MuERV's- include these lack LTR's with no internal reading frame (provirus) MuERVC, MuRRS, MuRVY's) These are mi Endogenous retroelements are mostly defective, they do Exogenous retroviruses are transmitted horizontally as represent mobile DNA that can re-integrate in other regions of the conventional viruses genome during cell division withour virion assembly and reLTR's encode superantigen LTR's include enhancers, promotors, which dictate infection MMTVtropism for mammary tissue gene (sag) transcriptional acitivty and tissue specificity

MuSV-sarcomavirus

incorporate a host cell protooncogene that directly alters cell division

Once in the viral genome they are called viral oncogenes and may be mutated to increase their pathogenicity, but also may be defective

Acute transforming retroviruses have such v-onc genes and are capable of transforming a cell quickly instead of relying on random insertional mutagenesis

MuLV

Exogenous and endogenous

transmitted through milk, semen, saliva, etc

Re-integration into the somatic genome results in random insertional mutagenesis and neoplasia follows integration near host proto-oncogenes

MMTV

Mammary gland neoplasia, lymphocytotropic

Mouse lymphoma - B cell and arise in spleen.

insertional mutagenesis can be endogenous or exogenous and transforms lymphocytes transmitted in milk

Bacterial Infections Enteric Infections

Citrobacter rodentium

Escherichia coli

Coliform typhlocolitis

Clostridium piliforme

Tyzzer's Disease

Helicobacter hepaticus

Salmonella

hyperplastic, catarrhal colitis; Induce non-flagellated, species specific, dissolution of brush bacterial colonization elicits intense requires direct contact, colonizes cecum Acquired immune response is border, actin filament mucosal epithelial hyperplasia/ cryptal Transmissible murine colonic and colon, attachment mediated by necessary for clearance but is DDX: hyperplastic colitis, E coli, Helicobacter, enterotropic rearrangement, cysts that fill with mucin; rectal prolapse; hyperplasia (TMCH) bacterial intimin and Type III proteins also a major factor in disease MHV pedestal formation contracted thickended colon, erosion, including translocated intimin receptor severity similar to attaching and multifocal hepatitis and splenitis (Tir) effacing E coli (EPEC and EHEC)

Typhimurium Enteritidis

Large intestinal hyperplastic lesions, thickended colon mucosa, mucosal hyperplasia

DDX: C rodentium, Helicobacter, Enterotropic MHV

red mucosa, multifocal liver necrosis with neutrophils, inflammation, necrosis myocyte degneration, myocarditis, in mucosa and intracellular bacteria muscularis

4mm white foci in liver, Hyperplastic typhlocolitis and hypertrophy and hepatitis hyperplasia of ito cells and oval cells intracellular, in macrophages

perineal fecal staining

fibriae to M cells--> phagocytosis by enterocytes--> replication--> to

DDX: MHV, mousepox, salmonellosis, pseudomoniasis, corynebacterium, Helicobacter spp, clostridial enteropathy

bile duct hyperplasia, fibrosis, helical microorganisms

mucosal crypt hyperplasia, organisms in crypt lumen

histiocytic granuloma

diarrhea, conjunctivitis, splenomegaly, pale liver foci, fibrinous peritonitis, venous thrombosis,

Hepatocellular tumors, typhlocolitis (IBD)

DDX: Salmonella, Proteus, Tyzzers, MHV, ectromelia

DDX: Tyzzer's, coronaviral hepatitis, mousepox, Helicobacter, pseudomoniasis

Chlamydiae

obligate intracellular

Chronic suppurative cranioventral bronchopneumonia with Warthin starry shows long filamentous marked peribronchiolar bacteria along cilia infiltration with lymphocytes and plasma cells

Cilia-Associated Respiratory Bacillus

Leptospira

Mycoplasma

pulmonary perivascular organisms grow within bronchiolar and peribronchiolar epithelium, type 1 alveolar cells, lymphocyte infiltration macrophages,, intracytoplasmic vesicles and non-suppurative containing inclusions interstitial pneumonia

Klebsiella

old mice with suppurative endometritis, cystic K oxytoca- suppurative female endometrial repro tract lesions hyperplasia, salpingitis, perioophoritis/ peritonitis (abscesses and adhesions)

interrogans ser icterohemorrhagiae

pulmonary fibrinoid vasculitis, renal tubular necrosis thrombosis, hemorrhage and interstitial nephritis

interrogans ser copenhageni

Lethal disease, discohesion of hepatic cords, hyperplasia of focal hepatic necrosis, Kupffer cells and macrophages,

M pulmonis

respiratory and genital tract disease ans sometimes arthritis

M neurolyitcum

Rolling disease

M Coccoides

transmitted by Polyplax serrata- louse

M hemomuris Lawsonia intracellularis

colonizes the apical cell membranes or respiratory epithelium, exacerbated by viral infections and Pasteurella exotoxin attahced to erythrocytes and free in plamsa

associated with viruses like Sendai and PVM

interstitial nephritis and tubular damage

Mitogenic for B cells

mucopurulent exudate, vestibular signs, bronchiolectasiss, abscessation, suppurative rhinitis, hyperplasia of mucosal glands

flat epithelium, syncytia, peribronchiolar and perivascular lymphocytes, metaplasia of respiratory epithelium

DDX: CAR bacillus, Sendai, Streptobacillus and Corynebacterium (Pneumonia and arthritis)

conjunctivitis severe anemia and death

typically infects rats Proloferative enteritis, typhlitis rats hamsters, guinea or colitis pigs and rabits Conjunctivitis, panophthalmitis, dacryoadenitis, Necrotizing dermatitis, mastitis, metritis, periorbital UTI, abortions abscressation, rhinitis, otitis, cervical lymphadenitis

Pasteurella pneumotropica

Respiratory, enteric and genital tracts

Proteus mirabilis

Suppurative pyelonephritis

splenomegaly, multifocal hepatic lesions in SCID mice

Fibrinous peritonitis

Pseudomonas aeruginosa

Conjunctivitis, nasal discharge

subcutaenous edema and sudden death

ulcerative lymphangitis, vasculitis, thrombosis, necrosis, hemorrhage

Coxiella burnetti

Mice that received bovine xenografts

necrotizing hepatitis, with Kupffer cell and Ito cell hyperplasia, and basophilic cytoplasmic inclusions

Streptobacillus monoliformis

Commensal of respiratory tract

Cervical lymphadenitis

ddx: fighting injuries, M pulmonis, pneumocystis, Sendai virus

septic thrombi in vessels DDX: Corynebacterium kutscheri, Enterobacter cloacae

Burkholderia gladioli

Clostridium perfringens Clostridium difficile Corynebacterium kutscheri

Staphylococci

Non-Type A, type B and Type large or small intestine D C diff toxin A and B liver, kidney, lungs, Pneumonia, caseous necrosis lymph nodes

Corynebacterium bovis

Hyperkeratosis

Corynebacterium spp

Conjunctivitis

Staphylococci

Conjunctivitis

lipophilic and grows in keratin

Suppurative embolic nephritis, polyarthritis, osteomyelitis

Rat Bite Fever- potentially fatal zoonotic

necrotizing and hyperplastic changes

generalized lymphoid apoptosis and renal tubular vacuolation

hematogenous

conjunctivitis, thrombosis, gram positive bacilli

Marked epidermal hyperplasia, orthokeratotic hyperkeratosis ans mononuclear and PMN cells in the dermis

DDX: pseudomoniasis, corynebacterial, staphylococcal, streptococcal infections, (mycoplasma and corynebacterium for arthritis) DDX: Tyzzer's disease, (and hyperplasia- citrobacter, Helicobacter, E coli) DDX: Staph, Strep, Mycoplasma (arthritis)

DDX: Low humidity, some other bacterial dermaitis DDX: Ectromelia virus, Pasteurella pneumotropica, Staphylococcus, Foreign bodies, genetic factors (entropion etc

Necrotizing dermatitis

Streptococci

hemolysins, nucleases, exfoliative exotoxins, leukocidin, proteases, lipases, Enterotoxins and Toxic shock syndrome hyaluronidase, toxin-1 collagenase

Lymphadenitis

Gram pos bacteria surrounded by splendore hoeppli material (botryomycosis)

Chronic disease can cause multisystemic amyloidosis and splenomegaly

Lancefield groups A, B, C, G

Group A- bacteremia, cervical lymphadenitis

Group B- Meningoencephalitis, ependymitits, periventriculitis, (from nose), pyelonephritis, septicemia

Strep agalactiae

Group B

DBA/2 mice with pyelonephritis and subsequent bacteriemia with disseminated lesions to the heart, kidneys, spleen, liver, uterus, thorax

Strep equisimilis

Group C

subcutaneous, hepatic, and abdominal abscesses

Group G

Necrotizing dermatitis with vasculitis and thrombosis

Enterotoccus

Lancefield group D

with Pseudomonas can cause bacteremia in SCID mice

M. avium intracellulare

asymptomatic with subpleural granulomas

Trichophyton mentagrophytes

Cuplike crusts on head ears, face, tail, extremities

Streptococcus

superficial colonization with underlying burn like lesions

B6 mice prone to trichotillomania causing DDX: other bacterial abscesses, Streptococcal necrotizing ulcerative dermatitis followed dermatitis, amputation of the tail (mousepox) by colonization with staph and then necrotizing dermatitis

enterococcus durans and faecalis

Mycobacteria DDX: M pulmonis, Corynebacterium kutscheri, Freunds adjuvant lesions

Mycotic Infections Dermatophytosis epithelial debris, exudate, mycelia, masses of arthrospores, with underlying dermatitis

Microsporum canis Systemic and Pulmonary

Cryptococcus neoformans

B6.129S6-Cybb mice

Candida tropicalis

B6-p47 Null mice

Defective NADPH oxidase Defective NADPH oxidase

Chronic granulomatous disease

Paecilomyces, Aspergillus, Rhizopus, Candida

Trichosporon beigelii

Actinomyces Gastric

Pneumocytsis murina

Candida pintolopesii

yeast of the surface mucosa of the glandular stomach

Pseudomemrane formation with epithelial hyperplasia and hyperkeratosis and leukocytes

Canida albicans

normal inhabitant

Pseudohyphae in the kersatinized layer

Non-filamentous yeast-like trophic forms

Asci (cysts) are also adhere to type 1 pneumocytes present and contain 8 ascospores

carriers are asymptomatic and disease Interstitial pneumonia with proteinaceous presents in immunosuppressed mice exudate in the alveolar lumina, thickening causing pneumonia of alveolar septa

3-5 um cysts, irregularly flattened

DDX: viral pneumonia, Sendai virus, PVM, Congestive heart failure

Parasitic disease Ectoparasites Acariasis

fur mites

Follicle Mites

Demodex musculi Psorergates

rare

Ornithonyssus bacoti

tropical rat mite

blood sucking intense pruritis

Pediculosis

Louse Polyplax serrata

Protozoal endoparasites Eimeria

vermiformis, falciformis, papillata, ferrisi

Cryptosporidium

muris

gastric mucosa, relatively non-pathogenic

Myobia, Radfordia, Mycoptes, Tichoecius

epidermal hyperplasia and hyperkeratosis

Myobia musculi

hypersensitivity

heavy infestations can result in anemia

DDX: Pediculosis, trauma, bacterial dermatitis, dermatophytosis, hair chewing, muzzle alopecia (mechanical) do not feed on blood but secretions; cause pruritis and self trauma leading to hair loss and secondary infections

Cryptosporidium

parvum

small intestine, marginally pathogenic

Giardia

muris

lumen of duodenum

Spironucleus

muris

(formerly hexamita)

Toxoplasma Sarcocystis Klossiella

gondii muris muris

Encephalitozoon cuniculi

microsporidiosis (more like fungi)

rare in lab mice rare in lab mice renal coccidiosis granulomatous hepatitis, interstitial nephritis, meningoencephalitis

enteritis secondary to viral infections poor hair coat, distention

cholangiohepatitis with focal hepatic necrosis, peribiliary fibrosis

commensal inghabitant crypts and intervillous spaces are of intestine distended, lymphocytes and plasma cells cats definitive hosts cats definitive hosts spores are gram positive

Helminths Oxyuriasis (pinworms)

rectal prolapse, intussusception, fecal impaction, diarrhea

Tapeworms

Rodentolepis

nana

Hymenolepis

diminuta

Rodentolepis

microstoma

Taenia taeniaformis (cysticercus fasciolaris)

mice ar intermediate host

AA

nana also capable of superinfections via direct ife cycles

cysticerci in lamina propria and threadlike adults adults in lumen

adults live in cats

larval form in stobilocercus (cysticercus fasciolaris)

scolex and segments within a cyst found in the liver (may resemble adult tapeworm)

serum precursor apoSAA

inflammatory response

spleen liver intestine and kidney

precursors are degraded by macrophages to AA fibrils

AapoAII

Primary or Senile Amyloid

produced by liver

Adrenals, intestine, heart, lungs, thyroid, parathyroid, ovaries, testes

nasal mucosa

some say it is not amyloid since it does not stain with Congo red and is trichrome positive

all use arthropods as intermediate hosts larger and intermediate forms do not appear in the mucosa as large as diminuta and often exist in bile ducts or pancreatic ducts inciting pancreatitis and cholangitis

Nutritional and Metabolic Amyloidosis

2 types

DDX: glomerular hyalinosis (agre related), glomerulonephritis, hydronephrosis, spontaneous cardiac atrial thrombosis

Soft Tissue Calcification

Acidophilic Macrophage Pneumonia/ Epithelial hyalinosis

Reye's like Syndrome

BALB/c

Epicardial mineralization with fibrosis of the RV free wall

C3H

foci of degeneration and mineralization throughout LV myocardium and IVS

Skeletal myofiber mineralization

DBA mice

epicardial and myocardial mineralization

dystophic mineralization in the aorta, testes, tongue, muscle, cornea, kidney, stomach, small intestine, ovary

in the tongue can form inflammatory polyps

B6, 129

cytoplasm packed with needle to rhomboid shaped crystals

Dystrophic mineralization of the superficial corneal stroma

DBA, C3H, BALB

AMP

focal to diffuse accumulation of acidophilic crystals within macrophages, alveolar spaces, and airways

Hyalinosis

part of the syndrome

hepatoencephalopathy and fatty degeneration of the viscera

Any disease that impairs normal pulmonary clearance can predispose to AMP

olfactory, nasal respiratory, middle ear, trachea, lung, stomach, In the cytoplasm of epithelial cells, with gall bladder, bile duct blebbing and filling of glands and pancreatic duct epithelium

anticedent viral infections and mitochondrial swelling aspirin therapy are with hepatocyte participating factors in dysfunction in the humans primary lesion

livers are swollen greasy and pale, kidneys are swollen

hepatic lipidosis, Alzheimers type II astrocytes, intestinal lesions associated with MHV are variable

self or conspecific

can initiate ulcerative dermatitis

Behavioral Disorders Male aggression

Stereotypy Barbering

DBA, Swiss, BALB/c Bar-mouthing, jumping, circling, somersaulting, routetracing tritrichotillomania

The presence of males will synchronize estrus (Witten effect)

diffuse wounds or centered around the tail and external genitalia

repetitive funtionless behavior females> males

B6 and A2G

DDX: BALB/c hepatic fatty degeneration (lesser degree of change)

Penis self mutilation

B6

Husbandry Mechanical muzzle alopecia Ringtail Cotton Sloughing Spinal fracture Dehydration Hypo-Hyperthermia Frostbite Ear gangrene and Notching

low humidity necrosis and sloughing of digits due to cotton fibers cage lid closure require large volumes of drinking water mice are inefficiaently homeothermic gangrene Albino Swiss and C3H

annular constrictions of the tail and feet

check for hydrocephalus

Massive thymic apoptosis Massive thymic apoptosis

nude mice prone

Aging Degenerative and Miscellaneous

Alopecia areata

C3H mice

irregular diffuse alopecia of the dorsal and ventral trunk

Alopecia of B6 mice

behavioral disorder

Myobia hypersensitivity

Clown Mouse syndrome

weaning age mice

runted and general alopecia

hairloss increases with age predispose to necrotizing dermatitis hyperkeratosis and glabrous skin

audiogenic siezures

domes, runted and dehydrated

reduced neuronal proliferation, defects in ependyma, lamination of cortex, microencephaly

DBA/2, SJL, LP

Hypocallosity

aplasia of corpus callosum

Hydrocephalus

C57Bl

Vacuolation of White Matter Multilaminated mineralized concretions Cochlear degeneration

thalamus of old mice

Spontaneous corneal opacity

acute to chronic inflammatory changes

vascularization, mineralization of corneal basement membranes

Blepharitis and Conjunctivitis

suppurative conjunctivitis

abscessation of meibomian glands

corynebacterium, staph, pasteurella pneumotropica

Microphthalmia and Anophthalmia

C57BL

females>males

assymetric

Retinal degeneration

Homozygous rd-1 allele

absence or degeneration of rods, outer nuclear layer, outer plexiform layer,

Malocclusion Foreign Body periodonittis Celft lip palate

B6 hereditary

Gastric mucosal hyperplasia Ileus in lactating mice Liver Problems- incidental Cytomegaly of hepatocytes Fatty change Eosinophilic cytoplasmic inclusions intranucelar cytoplasmic invaginations polyploidy, karyomegaly, anisokaryoiss, polykarya Biliary epithelial hyalinosis and crystals Bile duct proliferation

fixation artifact

smooth muscle I nthe abdominal segment etiology unknown abdominal distention

aplasia of the myenteric plexus with fibrosis

BALB-

normal

age related

Polyarteritis

small to medium sized arteries

Vestibular syndrome Atrial thrombosis and heart failure

manifestation of polyarteritis thrombosis of the auricle leading to heart failure

Perivascular lymphoid infiltrates Pulmonary histiocytosis

associated with MHV

neuronal necrosis of cortex, hippocampus, ejaculation with retention of urethral centrilobular coagulation necrosis of liver thalamus, generalized plugs resulting on obstructive uropathy gliosis

Siezures

Megaesophagus

dense anagen follicles with dystrophic hair follicles, melanin incontinence, interfollicular epidermal thickening, perifollicular mononuclear leukocyte infiltrates

fibrinoid degeneration and necrosis of tunica media Head tilt, circling precipitated by multisystemic amyloidosis

mild to severe in the adventitia antecedent to of pulmonary vessels lymphoproliferative disorders lipid laden macrophages

cholesterol or hemoglobin crystals

neutrophilic or mononuclear left side usually

usually incidental

Alveolar lipoproteinosis

progressive intraalveolar accumulation of granular pale eosinophilic phospholipid (surfactant)

Alveolar hemorrhage

extravasation of blood into alveolar spaces is common agonal finding

may overlap with hypertrophy and vacuolation acidophilic macrophage of Type II pneumocytes pneumonia

Freunds adjuvant pulmonary granulomata Aspiration pneumonia Murine Urologic Syndrome Chronic Glomerulonephritis/ Glomerulopathy

obstructive uropathy

cellulitis, paraphimosis, hydronephrosis

prostatitis, cystitis, urethritis, balanoposthitis

DDX- agonal release of coagulum from accessory sex glands

Amyloidosis Membranoproliferative glomerulonephritis LCMV and retroviruses

chronic progressive nephropathy (resembles the disease in Rats)

non-specific basement membrane thickening (glomerular hyalinosis)

glomerular sclerosis, tubular degeneration, regeneration, interstitial inflammation, dilated tubules with protein rich fluid

Hydronephrosis

usually incidentsl

DDX- renal papillary necrosis due to amyloidosis

renal Infarction Polycystic disesae

BALB/c Hyaline eosinophilic bodies in cytoplasm of tubules

association with histiocytic sarcomas

Inclusion body nephritis

Homogenous intranuclear eosinophilic inclusions

adjacent interstitial infiltrates of lymphocytes

negative for Polyoma virus, K virus, adenovirus

Chloroform Toxicity

Renal tubular necrosis

mineralization

Males > Females; castration eliminates sensitivity

may progress to chronic nephropathy

Pale kidneys with irregular outlines, tubular degeneration and atrophy in cortex and medulla one or both uterine horns dilated

Renal tubular hyaline bodies

NSAID nephropathy

Tubular degeneration with mineralization

Mucometra/hydrometra

BALB/c, B6, DBA

abdominal distension

aged female mice

may be associated with secondary bacterial pyometras

Cystic endometrial hyperplasia

Mammary Hyperplasia

glandular invasion of the myometrium virgin female FVB/N

Bulbourethral glands cysts

Adenomyosis

DBA and C3H mice

some have congenital imperforate vagina

DDX- Pyometra, retained fetuses, neoplasia

oftne extends to serosa

DDX- neoplasia

Small pear shaped

at the base of penis and embedded in skeletal muscle

secretions are part of copulatory plug

Cystic glands present as unilateral or bilateral swellings of the perineum

may be suppurative- Staph aureus, Pasteurella pneumotropica

sternebrae, vertebrae, femurs

aged female B6C3F1

bone marrow replaced by fibroblast like cells and osteoblasts embedded in an eosinophilic matrix

can extend into the periosteum; Non malignant

DDX- histiocytic sarcoma, osteosarcoma

small cell

multisystemic, lung , kidney, often with leukemic phase

Seminal Vesicular Dilatation and atrophy Pseudocanalization and Megalokaryocytosis of male reproductive epithelium Fibro-osseus lesions in Aged mice

Neoplasms Mammary Tumors Testicular Tumorsa Multicentric lymphoma Thymic lymphoma Hepatocellular neoplasia Lymhpoid and NonLymphoid Hematopoeitic Neoplasia Lymhphoid neoplasms

C3H/He 129/Sv BALB/c AKR DBA

B cell

Precursor B cell Mature B cell

spleninc marginal zone Follicular B cell

Diffuse large B cell Burkitt-lymphoma

arise in marginal zones and extend into both red and white pulp arise from follicles; typicallyu low grade Most common; spleen, Peyer's patches, and resemble germinal centers with large Mesenteric lymph nodes cells multifocal in spleen

Resemble follicular lymphomas

spleen, LN, mediastimum

spleens are enlarged; cells have abundant cytoplasm

arise from centroblasts in the splenic white pulp, medium sized with scant cytoplasm

can be histiocyte associated

Burkitt-like lymphoma Plasma cell

Lymphoblastic . Not Herpes virus associated Plasmacytoma Extraosseus plasmacytoma anaplastic plasmacytoma

B natural killer cell T cell

Precursor T cell Mature T cell

Cd4-/ Cd8-, CD3+

enlarged thymuses

Small cell

Splenomegaly, lymphadenomegaly, not Thymic associated

medium sized and uniform with scant cytoplasm

T-natural Killer cell Large cell anaplastic Non-Lymphoid neoplasms originates in the spleen, large vesicular nuclei, round, indented or can go to BM, liver, sparing of splenic follicles/ splenomegaly ring shaped lung, adrenal. Kidneys

Myeloid (granulocytic) Leukemias With maturation Without maturation Myeloproliferative disease-like myeloid leukemia Erythroid leukemias Megakaryocytic leukemia Biphenotypic leukemia hematopoeitic sarcoma Granulocytic

Histiocytic sarcoma

enlarged spleen, multifocal nodules in lungs, liver, ovaries, uterus, kidney, bone marrow, lymph nodes

large nuclei and multinucleated giant cells

erythrophagocytosis espiecially in the liver

Mast cell Myeloid dysplasia Myelodysplastic syndrome Cytopenia with increased blasts Non-reactive Myeloid proliferation Genetic myeloproliferation Myeloproliferative disease Mammary tumors Glandular

Acinar

composed of glands glandular structures with small MMTV's are either exogenous lumina (MMTV) or endogenous (low grade)

Cribriform

Sheets or nests forming lumina with round punched out spaces

Papillary

fingerlike projections of epithelium covering a central vascular core

Solid

solid sheets of epithelium with little or no glandular differentiation

Squamous Fibroadenoma Adenomyoepithelioma Adenosquamous NOS

multicentric and multinodular, well circumscribed, pulmonary metastasis is common

Squamous cells with or without differentiation, no glandular pattern Myxoid and fibrous stroma and glands myoepithelium and glands glandular and squamous elements Does not resemble any of the above

Pulmonary Tumors Primary pulmonary Adenoma

A strain is highly susceptible enhanced with viral infections due to a mutated K-ras allele such as Sendai

originate from Type II pneumocytes or its precursor common to Clara cells

Primary pulmonary adenocarcinoma Papilloma Squamous cell carcinoma Adenosquamous carcinoma neuroendocrine carcinoma Hepatocellular neoplasia Hepatocellular adenomas and carcinomas

closely packed cuboidal to lining remnants of alveolar septa with sparse collagenous stroma Sub-pleural masses +/- invasion and seeding of visceral and parietal pleura

Aged males > females

A and DBA strains

Helicobacter spp

Cells are non ciliated and may DDX- focal alveoalr epithelial cell hyperplasia (older mice) have mucinous differentiation

columnar cells

Antecedent: cell alteration, clear cell foci, grey to tan nodules, trabecular and solid basophilic foci, eosinophilic cell foci types,

well circumscribed, unencapsulated, anisokaryosis, karyomegaly, cytomegaly

Hepatoblastoma

organoid structures arranged around vascular channels

or forming rows and rosettes

Cholangioma Cholangiocarcinoma hemangioma hemangiosarcoma Histiocytic sarcoma Ito cell tumors (rare) Harderian gland tumors papillary cystadenomas or solid slow growing, appear late in adenomas life

Adenocarcinomas

highly invasive with infiltration of bone and othe rstructures of the head

Myoepitheliomas

BALB/c and BALB/cBy

protrusion of the eye with porphyrin staining

Females > Males

lobulated resilient, light tan to white mass in the retroorbital space

well differentiated epithelial cells with vacuolated cytoplasm

Arise from submaxillary may also be associated with mammary, and parotid salivary preputial, and Harderian glands glands

Reproductive Neoplasms Female Papillary cystadenomas ovarian tubular adenomas granulosa cell and thecal tumors Dysgerminomas hemangiomas/sarcomas Uterine endometrial stromal tumors adenocarcinomas Leiomyosarcomas Histiocytic sarcomas

rare urterus

Male Sebaceosquamous adenomas pregutial glands of both males and carcinomas and females Teratomas of the testis Extragonadla teratoma perigenital region Mesenchymal and Bone Neoplasms Rhabdomyosarcomas Mesenchymal tumors Soft tissue sarcomas Multicentric osteomas Primary Osteosarcomas

arise from skeletal muscle in BALB/cj, and BALB/cByJ can be induced by carcinogens and viruses Trp53 OF-1 mouse from spinal vertebrae, sternebrae and long bones

Moloney Murine Sarcoma Virus

metastasis to lung, liver, spleen, kidney

lumbosacral region

present with posterior paralysis

prolactin producing

Females > Males

Solid, sinusoidal, cystic, compress overlying brain

Endocrine Neoplasms Pituitary Gland Adenomas Adrenocortical adenomas Pheochromocytomas Pancreatic Islet tumors Thyroid Follicular cell Adenomas

B6 and Swiss mice, FVB/N

Cystic chambers containing serous fluid (necrosis)/ large pleiomorphic spindle cells with epithelial and mesenchymal features

metastasis to lungs, myeloid hyperplasia of bone marrow and spleen

Rats DNA Viral Infections Non-enveloped Adenovirus

DDX: Mouse Adenovirus

MAdV-2

Rat Cytomegalovirus

antigenically distinct from CMV

Serologically distinct from polyoma and K virus of mice

Pneumonia and sialoadenitis

Rats have a serologically related virus but do not have disease

Intranuclear inclusions in enterocytes

Enveloped Herpesvirus Salivary and Lacrimal cytomegaly with INIB Non-suppurative glands and ICIB interstitial inflammation

Polyomaviridae INIB in ductal epithelium

euthymic rats did not develop disease

Splenomegaly, liver necrosis, encephalomalacia

INIB in hepatocytes, endothelial cells and bile duct epithelium

cerebrallar hyoplasia, may have reproductive DDX- pseudomoniasis septicemia, hepatitis, and jaundice disorders Mycoplasma pulmonis, trauma in neonates

may be cowpox virus

Parvoviridae

Group 1

Group 2 Group 3

scrotal hemorrhage with peritesticular Kilhams rat virus (RV) fibrinous exudation, necrosis and infarction due to thrombosis H-3 X-14 RV-Y HER virus Toolan's H1 HT Rat Parvovirus (RPV)

Poxviridae Turkmenia rodent Poxvirus

related to cowpox, distinct from ectromelia

dermal pox and tail amputation

interstitial pneumonia

Sialodacryoadenitis Virus (SDAV)

also produce pulmonary disease in young rats

excessive lacrimation with crusts

parotid and submandibular salivary glands are swollen

Parkers Rat Coronavirus

rhinitis, tracheitis, interstitial pneumonia

salivary and lacrimal gland lesions

Hantavirus genus

aerosol and contact spread

Hantaan virus (HFRS)

no disease

HPS

Humans- pulmonary capillary leakage

Perivascular lymphohistiocytic interstitial alveolitis

some neutrophils and type II pneumocyte hyperplasia

RNA Virus Coronavirus

Bunyaviridae

Rat Respiratory Virus

ddx: Mycoplasma, Sendai, nonkeratinizing Pneumonia virus of mice coagulation necrosis of squamous metaplasia (pneumonia), Pseudomonas ductal structures of ducts (edema), stress events, ammonia in environment

Necrotixing tracheitis, flattening of Athymic nude rats epithelium, loss of develop chronic wasting cilia

Humansthrombocytopenia, myalgia,

DDX: Sendai, and Pneumonia virus of Mice

Paramyxoviridae

Pneumonia virus of Mice

Sendai Virus

Non-suppurative vasculitis and interstitial alveolitis with necrosis

Perivascular infiltrates, hyperplasia of BALT, perivasculitis

Parainfluenza 1

Mice, rat, hamster

respiratory epithelial necrosis

MHG RCaV

neurologic

mice, rats, hamsters, guinea pigs, gerbils

DDX: Sendai, Rat Respiratory virus, Rat coronavirus

rhinitis, neutrophils, plasma cells, lymphocytes

hyperplastic to suppurative bronchitis additive effect of and bronchiolitis with Mycoplasma infections perivascular and peribronchial cuffing

DDX: PVM, RRV, Rat corona,

Picornaviridae Rat Cardioviruses

Rotavirus villus attenuation, Infectious Diarrhea of necrosis of Infant Rats (IDIR) enterocytes, epithelial syncytia

Eosinophilic ICIB

DDX: E coli

Reovirus Rats do not have disesae, but seroconvert

Bacteria GRAM (-) Enteric Campylobacter

Young rats with diarrhea

Lawsonia Intracellularis Enterocyte necrosis, hepatocyte necrosis , myocardial necrosis with neutrophils and mononuclear cells

Dilation of SI with flaccid dialatation

Thickening of gut wall, Spleen- focal crypt epithelial septicemia, bacterial granulomas, fibrinous hyperplasia, emboli with fibrin and exudation and focal inflammation, focal exudate necrosis ulceration

focal liver necrosis

Suppurative Rhinitis

Bronchopneumonia with peribronchial lymphoid hyperplasia

Maybe concurrent infection with Rat coronavirus, Mycoplasma

Chronic suppurative bronchitis and bronchiolitis

Peribronchial cuffing with lymphocytes and use Warthin Starry stain plasma cells

Clostridium piliforme

Tyzzer's disease

filamentous weak gram negative, spore forming obligate intracellular

Helicobacter

Proliferative and ulcerative typhlitis, colitis, and proctitis

gastritis

Salmonella

enteritidis and typhimurium

Necrotizing and hemorrhagic ileitis

DDX- Pseudomoniasis, rotaviral enteritis, cryptosporidiosis, management issues and Tyzzers

GRAM (-) Respiratory Bordatella bronchispetica

Cilia-Associated Respiratory Bacillus Haemophilus

uncommon

important in guinea pigs and Rabbits

filamentous similar to primary argyrophilic bacillus mycoplasma infections

DDX- Mycoplasma , bacterial pneumonia, complications to Sendai, PVM, RRV, Rat Coronavirus

Murine Respiratory Mycoplasmosis

Pasteurella pneumotropica

M pulmonis

Catarrhal and suppurative bronchopneumonia

Intestine

Rhinitis, sinusitis, conjunctivitis, otitis media, suppurative bronchopneumonia, chronic necrotizing mastitis, pyometra

dark plum colored and multifocal abscesses tan

peribronchial cuffing with lymphocytes, metaplasia and hyperplasia of respiratory epithelium

genital tract lesions and otitis media

DDX: Corynebacterium kutscheri, CAR bacillus, Pasteurella pneumotropica metritis

GRAM (+) Respiratory

Corynebacterium kutscheri

Staphylococcus

Streptococcus pneumoniae

Multifocal suppurative /granulomatous necrotizing pneumonia (pseudotuberculosis)

Multifocal nephritis and hepatitis

rib cage, submandibular, neck, Ulcerative Dermatitis ears, head, with hair loss Botryomycosis heads Fibrinopurulent Suppurative polyserositis and bronchopneumonia meningitis

Fibrinous pleuritis

coagulation and caseous necrosis, hematogenous, interstitial pneumonia, perivascular cuffing

hyperplasia of epidermis,

bacteria in crust

DDX: Corynebacterium, Salmonella, Pseudomonas, Pasteurellosis

abdominal distention

gram postiive bacteria on villus tips of small intestine

formerly hemobartonella muris

transmitted by Polyplax spinulosa

Natural infections are inapparent

Klebsiella pneumonia

Opportunistic

abscesses in cervical, inguinal, mesenteric lymph nodes and kidney

Leptospira

subclinical with no lesions

Enterococcus faeciumdurans-2

Enteropathy in Infant Rats

Erysipelas

Fibrinopurulent polyarthritis, myocarditis, endocarditis

Mycoplasma haemomuris

Pseudomonas aeruginosa

Septicemia, pulmonary edema, Endocarditis, vasculitis Lung spleen, kidneys splenomegaly, with thrombosis visceral ecchymoses

Streptobacillus moniliformis

Rat Bite Fever

Zoonotic, maculopapular rash, fever, headache, polyarthritis

Bacterial Pyelonephritis/ Nephritis

E. coli, Klebsiella, Pseudomonas, Corynebacterium, Streptococcus, Enterococcus, Proteus

cystitis, proctatitis

DDX: Corynebacterium kutscheri, Pasteurella pneumotropica, Salmonellosis, Mycoplasma

Pulmonary Lesions of Unknown Etiology Eosinophilic Granulomatous Pneumonia

Brown Norway Rats

Multifocal pale tan to grey to red foci

Aspergillus fumigatus or niger

rhinitis with epithelial hyperplasia and squamous metaplasia

fungus found on epithelial surfaces

Trichophyton mentagrophytes

Dermatophytosis

Eosinophils, epithelioid macrophages, and MNGC

Mycotic Infections

Pneumocystis carinii/ wakefieldii

Hyperkeratosis, lesions on the neck epidermal hyperplasia, back and base of tail folliculitis, arthrospores in hair shafts,

alveoli contain foamy Numerous black pink material with trophozoites and honeycomb yeastlike cysts 3-5um appearance in the alveoli

Type II pneumocyte proliferation and interstitial fibrosis

Parasitic Diseases Lice

Fleas

Mites

Polyplax spinulosa

vector for Mycoplasma haemomuris

pruritis, anemia

Holopleura pacifica Xenopsylla Leptopsylla Nosopsyllus Radfordia ensifera (myobia ratti) Demodex spp Notoedres muris

Cryptosporidium

diarrhea and high mortality

Tryanosomiasis

Trypanosoma lewisi

Giardia muris

small intestine

disfigurment of the ear Hyperplastic mucosa and blunted villi with fusion infected by ingestioin of fleas or flea feces

giemsa stained blood films

Catarrhal enteritis with weight loss

Spironucleus muris Helminths Pinworms (nematode): Oxyuris

Syphacia obvelata

cecum and colon

Syphacia muris Aspiculuris tetraptera Other nematodes Trichosomoides crassicauda Tapeworms Rodentolepis and Hymenolepis

urinary tract

found in lumen and bladder mucosa and renal pelvis

Rodentolepis nana

arthropod intermediate host

eggs deposited in colon rectal prolapse, and perianal area, impactions, diarrhea, embryonate and intussusceptions become infectious

R. Microstoma Hymenolepis diminuta

Taenia taeniaformis

eggs ingested--> Cysticercus fasciolaris migrate through is the larval stage bowel--> encyst in liver of mice (cysticercosis)

Aging and Degenerative Disorders Chronic Progressive Nephropathy/ Nephrosis

Males> females

Nephrocalcinosis

various dietary factors

Hydronephrosis

Urinary Calculi

don’t confuse with agonal copulatory plugs

Hematuria/ renal Papillary Hyperplasia

associated with hydronephrosis

Polyarteritis

Sarcomas may develop around the cysticerci

chronic glomerulopathy/ glomerulosclerosis/ interstitial fibrosis

proteinuria/casts/ PAS positive hyaline droplets

secondary changes: Hyperparathyroidism, mineralization

Nephrotic syndromehypercholesterolemia, hypoproteinemia, BUN/CT

Brown Norway Ratautosomal polygenetic disorder Gunn Rat_ autosomal dominant S-D: highly heritable

Myocardial Degeneration and Necrosis

pitted and irregular with pallor

Cat eats mouse and becomes Taenia taeniaformis

SPF SD rats

DDX: pyrelonephritis, polycystic kidneys, renal papillary necrosis

may be due to urethral obstruction by sperma

renal papilla have focal proliferation with necrosis and hemorrhage

M>F

Aging rats

M>F

Alveolar histiocytosis/ Alveolar proteinosis

dull pale yellow foci, subpleural

Intra-alveolar macrophages with needle shaped crystals and vacuolated or homogenous eosinophilic material

Degenerative nervous system changes

Wallerian degeneration in focal areas of the spinal cord

Segmental demyelination of the peripheral nervous sytem

ventricular hypertrophy and pale streaks

Mesenteric vessels, tortuous and thickened

Spontaneous radiculoneuropathyspinal root degeneration with muslce atrophy of the lumbar region and hind limbs

vacuolation of the cytoplasm. Fragmentation of sarcoplasm, loss of cross striations, mono-nuclear cell inflammation

interstitial fibrosis with proliferation of fibrous tissue

microscopic lesions not in lung

fibrinoid degeneration and thickening of the mononuclear cells with media of affected few neutrophils, arteries with smudging thrombosis of the normal architecture

Polyploidy, megalokarya, binuclear hepatocytes, intranuclear cytoplasmic invaginations

Focal sinusoidal dilatation and peliosis, either spontaneous or drug induced

Bile ductular proliferation, lined by atrophic epithelium, surrounded by collagenous tissue

Malocclusion

secondry to poor alignment of upper and lower incisor teeth

spontaneous/genetic

cellultis and salivation are sequela

Ringtail

Annular constrictions of the skin of the tail leading to dry gangrene

attributed to low environmental humidity

genetic factors, low environmental temps, degree of hydration, and nutrition may be involved

Epidermal hyperplasia with orthokeratotic and parakeratotis hyperkeratosis

Dehydration

accompanied by porphyrin staining around the eyes (sign of stress) progressive reduction Advanced disease has albino rats are of photoreceptor nuclei marked depletion and predisposed due to in the outer nuclear alteration of the retinal unpigmented uveal layer of the central layers with cataract tracts retina formation

this muct be distinguished from peripheral retinal degeneration (inherited disorder)

Liver changes

Miscellaneous Disorders

Retinal Degeneration

Corneal lesions

Bedding

Lacrimal gland Conjunctivitisdysfunction- following Pasteurella, rat coronavirus- virus environmental factors damages the harderian gland (KCS) dusty bedding predisposes to aspiration pneumonia

Chloral Hydrate Ileus

Auricular Chondritis

SD/ Wistar Rats

Multinodular, granulomatous inflammatory foci with chondrolysis and invasion by mesenchymal cells

Neopalsia Large Granular Lymphocytic Leukemia Lymphoma/ Leukemia

Splenomegaly with DDX- Lymphoma and erythrophagocytosis histiocytic sarcoma Splenomegaly, enlarged lymph nodes, hepatomegaly

epitheliotropic/ circumscribed medium to large size, Cutaneous Lymphoma erythematous plaques T cell lymphocytes and (mycosis fungoides) pregressing to dissociated adjacent ulceration epidermal cells

anemia and icterus

Dilated and thrombosed vessels, necross, hemorrhage

Histiocytic Sarcoma

SD/ Wistar Rats

Liver, LN, Lung, Vesicular nuclei, ample Spleen, Mediastinum, cytoplasm, MNGC Retropertoneum

morphology varies from sheets to pallisading and streaming fusiform cells

Mammary Tumors Fibroadenoma

SD females; recurrence is likely

retroviruses not involved

Carcinoima

rare

variety of patterns

circumscribed moveable firm lobular mass

interlobular and intralobular connective tissue

Prolactin secreting tumors most common; may contribute to mammary tumors

pars distalis

may consist of primarily connective tissue, or epithelial cells predominate

Pituitary gland tumors

majority/ SD/ Wistar Chromophobe adenoma rats

IHC required for positive identification

Testicular Tumors

Interstitial cell tumor

F344 older males

Mesothelioma

F344

Holocrine gland at the Zymbals Gland Tumors base of the ear

Other

also have smaller polyhedral to elongated cells with lobulated light yellow` cells with granular hyperchromatic nuclei vacuolated cytoplasm and scant cytoplasm

concurrent hypercalcemia

Tunica vaginalis of testis

circumscribed and ulcerated

sheets of epithelial cells with abundant vacuolated cytoplasm, with necrosis and leukocytes

adenoma or adenoacarcinoma

Polyhedral cells and acinar structures containing keratinized material and debris

Hamsters DNA Viral Infections Non-enveloped Adenovirus General

Ileal enterocytes

Large amphophilic intranuclear inclusions,rarely in crypts, asymptomatic

Cytomegalovirus

Acinar epithelium

Enveloped Herpesvirus Salivary and Lacrimal glands

cytomegaly with INIB and ICIB

Parvoviridae

Missing incisor teeth

New Strain: enamel H-1: necrosis and hypoplasia, inflammation of dental pulp periodontitis, with mononuclear leukocytic suppuration and infiltration of the dental lamina mineralization, and osteoclasiss of alveolar hemorrhage in dental bone pulp

Multifocal cerebellar and cerebral hemorrhage and thrombosis with transmural hemorrhage

Polyomavirus Transmissible Lymphoma

Hamster Polyoma Virus

keratinizing skin tumors of hair follicle origin

can be papilloma like

Lymphoma

Abdominal masses, large lymph nodes

Non glabrous skin- keratinizing follicular structures reminiscent of trichoepitheliomas

liver, kidney, thymus

RNA Virus Arenaviral infection

Paramyxovirus Sendai virus

Bacteria

chronic wasting, lymphocytic vasculitis and Lymphocytic infiltration into the liver, lung, glomerulitis with Ag/Ab Choriomeningitis (LCM) spleen, meninges, and brain complexes in glomeruli Pneumonia virus of Mice (PVM)

unknown significance

Interstitial pneumonia with consolidation

Segmental rhinitis --> necrotizing tracheitis and bronchoalveolitis

antigen in respiratory epithelium

Zoonotic (mild influenza like to meningitis)

hyperplasia of epithelium follows infection plus peribronchiolar lymphocytes

usually lymphoid but erythroblastic, reticulosarcomatous, and myeloid types have been described, sometimes plasmacytoid features

GRAM (-) Enteric Campylobacter jejuni

co infection with Lawsonia

Zoonotic

Lawsonia intracellularis

Runted and emaciated hamsters

soiling of perineum

Tyzzer's

Clostridium Piliforme

intracellular

Hepatic necrosis, Ileum focal granulomatous myocarditis , cecum, colon with conspicuous bulging nodules

yellow to dark red fluid, blunting and fusion of villi, lined by cuboidal epithelium

neutrophilic inflammation

Gastric antrum and pyloric duodenal junction

Gastric mucosal hyperplasia to dysplasia

may progress to carcinoma

Proliferative and dysplastic typhlocolitis

mucosal thickening and sibmucosal edema, hypertrophy of enterocytes

E coil

Helicobacter

Segmentally thickened ileum with prominent varying necrosis and hemorrhage, crypt marked crypt and villus epithelial serosal nodules and abscesses, granulomatous hyperplasia, villus elongation fibrinous peritoneal inflammation attachments

focal necrosis fo liver, with neutrophils

DDX: Salmonella, Coliform enteritis, Antibiotic associated C difficile, Campylobacter DDX: Clostridium, Lawsonia, Salmonella

Cholangiofibrosis (H Cholecystis) Salmonella

Liver: Pinpoint necrosis, with thrombosis

Lung: hemorrhage, interstitial Spleen: focal necrosis pneumonia, and and splenitis thrombophlebitis

Embolic glomerulonpehritis

Gram (+) Enteric Antibiotic -associated Enterocolitis

Clostridium difficile

Non-Antibiotic-associated

Clostridium difficile

Cecal mucosal hypertrophy of ceca ar congested Unknown etiology contracted and opaque

Lincomycin, clindamycin, cecum is distended mild pseudomembranous typhlitis. ampicillin, vancomycin, DDX: Salmonella, Enteropathogenic E with gas and tan to red Effacement of epithelium, edema erythromycin, cephalosporins, Coli, Tyzzer's dz fluid contents of LP, mucosal hyperplasia gentamicin, penicillin Necrotizing to hemorrhagic typhlitis increased mitotic activity and hyperplasia of enterocytes lining the crypts

Gram (+) Respiratory Corynebacterium kutscheri Streptococcus pseumoniae S. agalactia Gram (-)

local granulomatous and suppurative lesions

oral cavity, lymph nodes

high fat diet

Francisella tularensis

ruffled fur, lungs had mottled hemorrhage, Lymphoid necrosis and focal livers pale and seollen, hemorrhages and bacteria spleens enlarged

Leptospira ballum

hemolysis, jaundice, nephritis, hepatitis

Yersinia pseudotuberculosis

Chronic emaciation with intermittent diarrhea

Pasteurella pseumotropica and others Mycoplasma pulmonis Mastitis Strep P pneumotropica E coli Cutaneous and cervical abscess Actinomyces bovis Staphylococcus aureus Streptococcus Pasteurella pneumotropica

Caseous nodules in intestine, mesenteric lymph nodes, liver, spleen, and lungs

URI, Otitis, Bronchopneumonia

Parasites Ectopic Mites (Acariasis) Demodex Notoedres notoedres

criceti aurati burrows in stratum corneum

Notoedres cati Ornithonyssus bacoti and sylvarium Myiasis Wohlfahrtia vigil Sarcophaga haemorrhoidalis Musca domestica Endoparasites Spironucleus muris Cryptosporidium Giardia misocricetus

intestinal flagellate

incidental finding

Giardia muris

mostly asymptomatic

chronic lesions- thickening of SI cecum and colon

Microscporidia

Encephalitozoon cuniculi

Nematodes Pinworms

Syphacia criceti S mesocriceti S obvelata S muris nasalis

more common

fasciolaris microstoma Nana diminuta

(Taenia taeniaformis) Lower small intestine Lower small intestine upper small intestine

Spontaneous Hemorrhagic Necrosis (SHN) of the CNS of fetal hamsters

Stillborn or weak

Prosencephalon: Symmetrical, subependymal, vascular degeneration, with edema and hemorrhage

Diabetes Mellitus

Recessive in Chinese hamsters

Weight loss, glucose intolerance, hyperglycemia, polyuria, polydypsia, hypoinsulinemia, ketonuria

Trichosomoides

Tapeworms Cysticercus Rodentolepis Hymenolepis

dogs and cats

Nutritional and Metabolic Disorders intraventricular hemorrhage

strain related variations to susceptibility

Environmental Genetic and Other Disorders degeneration and atrophy of necrosis and ulceration the digits, with granulomatous with foreign body inflammation dermatitis

Bedding-associated Dermatitis

Wood shavingsfootpads

Malocclusion Congenital/ Hereditary Hydrocephalus Periodontal Disease

No obvious changes in behavior

doming of the calvaria was absent

Pugilism

Females are aggressive

Chinese hamsters

Inconsistent and permissive

Low temps, short days, solitude, nesting material, inadequate food stores

stenosis of cerebral aqueduct

Cannibalism Hibernation and Estivation

Age related disorders

high temps, low water may stimulate estivation

DDX: trauma and cannibalism

Vitamin E related/ deficiency

Hamster Glomerulopathy (arteriolar Nephrosclerosis)young animals

Gross: Pale granular with irregular cortical depressions; radiating cortical scarring

Histo: Thickening of BM with eosinophilic material

Amyloidosis (older animals)

Females > Males

Hamster female protein similar to Amyloid P

Gross: pale, irregular Histo: Amyloid in glomeruli, tubular granular capsule, livers BM, portal triads, intestine are swollen

Left auricle and atrium

often associated with amyloidosis

focla to diffuse myocardial bilateral ventricle degeneration; medial degeneration hypertrophy is common and calcification of coronary arteries

Atrial Thrombosis

may be concurrent amyloid in advanced lesions

variable degeneration of tubules and minimal inflammatory response, proteinaceous casts, fibrinoid change in vessels

Cysts are thin walled pressure atrophy of hepatic cords, containing clear straw Polycystic Disease (polycystic Multiple Hepatic cysts in epididymis, seminal vesicles, hemosiderin, proliferation of bile colored fluid lined by Liver Disease) older hamsters pancreas, endometrium ducts, periportal lymphocytic flattened to cuboidal infiltration epothelium spontaneous, uniform nodularity, periportal fibrosis, bile duct proliferation

nodular hepatocellular degeneration, necrosis, and mixed leukocyte infiltration

Lymphoma

Polyoma virus or spontaneous

spontaneous tumors are Multicentric, thymus, lymph nodes, spleen, liver

Cutaneous Lymphoma resmbling mycosis fungioides

epidermotropic

Bile Ductular Hyperplasia/ Hepatic cirrhosis Alveolar Histiocytosis Fibrinoid degeneration of arterioles

Neoplasia

Adrenocortical adenomas

Gerbils Virus Reovirus type 3

degenerative lesions in pancreas and focal necrotic lesions in the CNS

Bacterial Infections

Tyzzer's Disease

Clostridium piliforme

Antibiotic associated enterocolitis

Clostridium difficile

Citrobacter rodentium Salmonella

typhimurium Group D

Staphylococcal dermatitis

Staph aureus

Nasal Dermatitis

S Aureus and S xylosus

Bordetella bronchiseptica

older animals are resistant, younger animals can have severe mortality

Ciliary Associated Respiratory Bacillus

asymptomatic

Leptospirosis

Helicobacter pylori

Parasitic Diseases Demodex Giardia

Multifocal periportal necrosis in liver with neutrophils and macrophages/ Focal fibrosis

Upper small intestine

focal Peyer's patch necrosis, lymph node mecrosis, myocardial necrosis with myofiber collapse, and leukocyte infiltration

following Amoxycillin and Metronidazole bloody diarrhea, thickening of goblet cell hyperplasia the colon and rectum diarrhea, dehydration high mortality testicular enlargement, focal hepatitis, splenic necrosis, pyogranulomatous suppurative orchitis, interstitial leptomeningitis pneumonia gross- moist dermatitis of face, nose, feet, legs, ventral abdomen

Histo- suppurative dermatitis with acanthosis and hyperkeratosis

dermatitis and alopecia

porphyrin containing lacrymal secretions have been an important contributing factor

Acute didseasehemolytic anemia, Chronic- Renal interstitial icterus, centrilobular fibrosis, inflammation, cysts, liver necrosis, necrosis of renal tubules chronic gastritis, gastric ulcers, gastrointestinal metaplasia, gastric adenocarcinoma

Ileum and cecum, necrosis and sloughing, blunting, edema, neutrophils and macrophages,

not natural infection

may become ulcerative

diffuse suppurative encephalitis

DDX: Cl. Difficile, salmonella

Pinworms Tapeworms Genetic Disease

Epilepsy

Dentostomella translucida Rodentolepis nana

no histopathologic lesions

no clinical problems

twitching of vibrissae and pinnae, motor arrest, myoclonic jerks, clonic-tonic siezures, vestibular alterations

Periodontal disease and dental caries Malocclusion Behavioral disease Toxic and Metabolic Disorders Streptomycin Toxicity

Direct neuromuscular blocking by inhibition of acetylcholine release

Lead Toxicity

Chronic progressive nephropathy with acid fast intrnuclear inclusions in renal proximal tubular epithelium

Amyloidosis

filariid worm

Obesity and diabetes

reduced glucose tolerance, elevated insulin, and hyperplastic or degenerative changes in the endocrine pancreas

Hyperadrenocorticism/Cardiov ascular disease

only bred animala

Age related disease Focal myocardial degeneration

necrosis and fibrosis

Lipofuscin pigment granules microcytic hypochromic in hepatocytes and Kupffer anemia with basophilic cells stippling

DDX: Age related glomerulonephropathy, and erythrocytic basophilic stippling

liver, spleen, lymph nodes

elevated serum plaquesof intimal and medial triglycerides, enlarged ground substance with pancreatic islets. Fatty mineralization of the aorta livers, thymic and mesenteric, renal, and involution, peripheral arteries pheochromocytoma

focal myocardial necrosis and fibrosis

Chronic glomerulopathy

Aural cholesteatoma

glomerular hypercellularity, thickening of glomerular basement membranes, tubular degeneration with dilatation and cast formation, mononuclear cell interstitial inflammation

Keratinized epithelium displaces tympanum into arising from outer moddle ear with compression tympanic membrane and secondary inflammation and external auditoryt resulting on destruction of canal temporal bone and iner ear

Cystic ovaries

ovulation and corpus luteum formation continue

Ocular proptosis

protrusion of the nictitating membrane and conjunctiva with bulbar proptosis

Neoplasms Mongolian gerbils

Other species

Ovarian Adrenocortical cutaneous Granulosa cell tumors Dysgerminoma luteal cell tumors leiomyomas thecal cell carcinoma Marking gland males, ventral marking glands adenocarcinoma Squamous cell carcinoma thymoma Hodgkin-like lymphoma Uterine adenocarcinoma

Helicobacter pylori

adrenocortical tumors primary ovarian tumors Gastric carcinoma

head tilt and keratin plugs in external ear canal

Guinea Pigs Kurloff cells

Pulmonary arterial medial thickening Adventitial lymphocytes in pulmonary vesels

finely granular cytoplasmic inclusions found in spleen and bone marrow and thymus normal normal

Osseous metaplasia

in lungs

Thymus

degenerate thymocytes near Hassals corpuscles

Cardiac glycogenosis (Rhabdomyomatosis)

NK counterpart

lamellar bone with varying degrees of calcification

not significant

incidental degenerative pale pink poorly delineated condition and congenital foci or streaks mostly in left tissue malformation with ventricle blastemoid features

DNA Viral Infections Non-enveloped Adenovirus

Adenoviral Pneumonia

Low morbidity and mortality

necrotizing bronchitis and bronchiolitis with consolidation of cranial lung desquamation of lingin lobes and hilus epithelial cells and leukocytic inflammation with fibrin

Intramuclear round basophilic 7-15 um inclusions

Enveloped Herpesvirus Cytomegalovirus

CMV group

Guinea pig herpes-like virus (GPHLV)

kidney cell cultures

Guniea Pig X virus (GPXV)

isolated from leukocytes

Retrovirus Cavian Leukemia RNA Viral Infections

Retrovirus Type C

humans, primates, mice, rats, guinea pigs

focal hepatic necrosis and mortality

Karyomegaly and intranuclear and intracytoplasmic inclusions

Ductal epithelial cells, salivary glands, kidneys, liver, lung

DDX: Parainfluenza, cytomegalovirus, bacteria (bordatella)

Arenavirus

Lymphocytic Choriomeningitis (LCM)

Coronavirus-like Infection

Typical lesions and disease

Parainfluenza-3 (PI-3)

interstitial pneumonia and alveolitis with pulmonary congestion and hemorrhage, relative sparing of airways

Paramyxovirus

Picornavirus

Pneumonia virus of mice Sendai virus Murine Encephalomyelitis Virus strain GDVII Murine Poliovirus

lymphocytic infiltrates in the meninges, choroid plexi, ependyma, and liver, adrenals, lungs,

Lameness

Bacterial Infections Enteric Infection Antibiotic Associated Dysbacteriosis (antibiotic toxicity)

Clostridial disease

Clostridium difficile

cecum atonic and dilated with fluid and gas, enterotoxin recovered mucosa is hemorrhagic and edematous

Spontaneous Clostridial Enterotyphlitis

Clostridium perfringens Type A Clostridium piliforme C difficile

Tyzzer's Disease

Clostridium piliforme

organisms in enterocytes

Adenomatous Intestinal Hyperplasia

Lawsonia intracellularis

intracellular bacteria in enterocytes

Salmonella

typhimurium

multifocal pale foci in liver and spleen

necrotizing fibrinous enteritis, colitis

acute form: miliary creamcolored nodules in the intestine wall in ileum and cecum

subacute to chronic: miliary caseous nodules in mesenteric lymph nodes and spleen, liver and lung

necrosis of epithelium

necrotizing ileitis and typhlitis, frequently transmural

enteritidis

Pseudotuberculosis

Yersinia pseudotuberculosis

granulomatous hepatitis, splenitis, lymphadenitis

hyperplasia of the mucosa with mononuclear cell infiltration on the LP

Respiratory Infection

Bordetella bronchiseptica

Guinea pig Inclusion Conjunctivitis

mucopurulent or catarrhal exudate in nares, nasal passages, and trachea

red conjunctiva, purulent Chlamydophila caviae exudate, sloughed epithelium, (formerly Chlamydia intracytoplasmic inclusioins psittaci) and bacteria

Citrobacter fruendii

pneumonia, pleuritis, enteritis

Klebsiella

septicemia, necrotizing bronchopneumonia, pleuritis, pericarditis, peritonitis, splenic hyperplasia

Pseudomonas aeruginosa Streptobacillus moniliformis

pleuritis, typanitis, chronic suppurative bronchopneumonia, heterophilic, obliteration of normal architecture

Pulmonary botryomycosis cervical lymphadenitis, pyogranulomatous bronchopneumonia

sulfur granules

Staphylococcus

Ulcerative pododermatitis (bumblefoot)

secondary to trauma, poor sanitation

Staphylococcus dermatitis

erythema, hairloss, scabs, ventral abdomen and extrematies

epidermal cleavage, parakeratosis

Streptococcus

zooepidemicus group C

suppurative lymphadenitis

Diplococcal (pneumococcal) infection

S. pneumoniae

no toxins, just resistant to phagocytosis

Bacterial Syndromes Otitis media

Bacterial Mastitis

S pneumonia S zooepidemicus Bordetella Pseudomonas E coli Klebsiella

plantar surface is swollen and painful with necrosis

amyolid in the spleen, liver, adrenals and islets in rare cases

abrasions in oral mucosa

cervical lymph nodes, retrobulbar abscess, otitis media, bronchopneumonia, pericarditis

fibrinopurulent pleuritis, bronchopneumonia with pericarditis, peritonitis fibrin

ddx: Strep, Bordetella,

Bacterial Conjunctivitis

Strep zooepidemicus Chlamydia Strep zooepidemicus Staph aureus Pasteurella multocida

Mycotic infections Dermatophytosis

Trichophyton mentagrophytes

scaly pruritic, alopecia, hyperkeratosis, epidermal hyperplasia, pustules, folliculitis, arthrospores

Microsporum canis Parasitic Diseases Ectoparasites

Acariasis

Trixacarus caviae

Sarcoptic mange

ortho and parakeratosis, heterophils, eosinophils, inner thighs, neck , flaccid paralysis, shoulders, abdomen epidermal hyperplasia, stratum corneum contains mites and eggs

Demodex caviae Pediculosis (lice)

Gliricola porcelli

Large biting lice

pruritis, rough hair coat, alopecia

Gyropus ovalis Endoparasite

Protozoa

Cryptosporidium wrairi

juveniles

thin, potbellied, fecal staining, jejunum, ileum, cecum

hyperplasia of crypt epithelium, edema of lamina propria, necrosis and sloughing of enterocytes, villous atrophy

Eimeria caviae

intestine contains fluid, mucosa is congested, edematous, with petechia

colonic hyperplasia, sloughing of enterocytes, PMNS and mononuclear cells

micro and macrogametocytes

ddx: Crypto, clostridium, dysbacteriosis

renal coccidiosis

schizogony in endothelium of glomerular capillaries-> rupture --> schgizogony repeated in tubular epithelium

Gametogeny occurs in epithelium of Loops of Henle--> sporulated occysts are released in urine

oocysts are ingested and invade intestinal capillaries--> kidneys

Klossiella cobayae

Helminth

Encephalitozoon cuniculi (microsporidiosis)

granulomatous encephalitis, interstitial nephritis

Toxoplasma

asymptomatic

hepatitis, pneumonia, myocardial cysts, CNS cysts

larval migrans- cerebral malacia, eosinophilic Baylisascaris procyonis granulomatous inflammation with nematode larvae cecal worms up to 25 mm in Paraspidodera uncinata length, also located in colonic mucosa

asymptomatic

Nutritional, Metabolic and others Scurvey

Hypovitaminosis C

deficient in L-gulonolactone oxidase (converts Lgulonolacotne to L-ascorbic acid)

primates, guinea pigs, required for formation of indian fruit bat, some hydroxyproline and birds, some fish, and hydroxylysine in collagen cetaceans molecules

deficient in interstitial and osteoid production

Lesions: Persistent primary spongiosa C is required for (retained cartilage cores), cholesterol to bile acid and reduced osteoid formation production. Calcified cartilgae is susceptible to microfractures increased capillary fragility

enlargemnet of costochondral junction with hemorrhage; proliferation of poorly differentiated fusiform mesencgymal cells in periosteal regions and medullary cavity;; aggregates of eosinphilic mateiral interspersed between the mesenchymal cells; dental anomalies- fibrosis of pulp and derangement of odontoblasts

periarticular hemorrhage

widening of intercellular spaces between endothelial cells, vacuolar degeneration and depletion of subendothelial collagenous tissue// Increased pro-thrombin time

increased susceptibility to streptococcus hemosiderin laden pneumoniae (impaired macrophages in lamina macrophage migration propria of intestine and heterophil phagocytosis)

Necrotizing myopathy

idiopathic necrosis with DDX: nutritonal muscular leukocyte infiltration, dystrophy, spontaneous loss of cross striations, muscular mineralization with and mononuclear cell degeneration infiltrate

Nutritional muscular dystrophy

Vit E/ Se deficiency

Myocardial and Skeletal Muscle Degeneration with mineralization

may be incidental finding

Metastatic Calcification

> 1 year old

Pregnancy Toxemia (Hepatic lipidosis with ketosis)

Fasting or Metabolic Form

pallor of affected muscles, multinucleated muscle coagulative necrosis and fibers may be present hyalinization of myofibers, in regenerating testicular degeneration is fragmentation of sarcoplasm, myofibers, a later development increased basophilia of mineralization is not an sarcoplasm, rowing of nuclei, important feature and regeneration

soft tissues around the elbows and ribs

acidosis, ketosis, proteinuria, ketonuria, low urine pH (acidosis) Circulatory or Toxic form (preecclampsia)

Diabetes Mellitus

infectious agent unidentified

vacuolation of and degranulation of islet Beta cells with fatty infiltration of the exocrine cells

Alopecia

advanced pregnancy and lactation

back and rump

Malocclusion

molar and premolars

genetics and fluorosis

Gastric dilatation and vovlulus

low magnesium and high lung, trachea, heart, phosphorus(high Ca and aorta, liver, kidney, P diets interfere with Mg stomach, uterus, sclera absorption) end of pregnancy

lowblood glucose, ketosis, hyperlipidemia

uteroplacental ischemia due to compression of the aorta

placental necrosis, hemorrhage, ketosis, and death, periportal liver necrosis, leukocyte, nephrosis,

ddx: barbering, pediculosis, dermatophyte

Cecal torsion Intestinal hemosiderosis Focal Hepatic necrosis

lamina propria Subcapsular

Chronic Idiopathic Cholangiofibrosis

Periportal fibrosis, hepatocyte degeneration and interstitial fibrosis, proliferation of cholangioles

Liver contusions Foreign body pneumonia (Pneumoconiosis)

traumatic fractures aspirated food or bedding

Adjuvant associated pulmonary granulomas Behavior

considered terminal

ddx: Tyzzer's

granulomatous bronchiolitis, or pneumonia

ddx: perivascular Subcutaneous injections Lung: multifocal lymphoid nodules, with Freunds adjuvant granulomatous inflammation pneumoconiosis, focal pneumonia ear chewing and hair pulling

Diseases of Aging Segmental Nephrosclerosis

Cystitis and urolithiasis

Ovarian cysts

Fatty infiltration of pancreas

irregular pitted granular cortices

pale linear streaks extend down into the cortex

Fecal contaminants such as E coli

thick bladder mucosa, congestion intraluminal hemorrhage, mononuclear leukocytes, fibroblast proliferation, urinary calculi

rete ovarii- large fluid filled cysts on the cystic endometrial surface (cysts are hyperplasia, mucometra, continous with follicles endometritis, fibroleiomyomas and mesovarium) large areas of adipose tissue between normal panreatic acini

Neoplasia' serum factor (Asparaginase) has anti tumor effects Kurloff cells act as NK cells Hematopoietic

Cavian Leukemia

gross- lymph node Lymphoblastic cells in spleen. enlargement (cervical, Liver, BM, interstitium of lung, axillary, mesenteric, thymus, alimentary tract, and inguinal), lymphoid tissue, heart, eyes, Splenomegaly, and adrenals Hepatomegaly,

interstitial fibrosis, tubular dilatation

interstitial lymhpocytes

Reproductive tract Ovary Uterus (benign) Uterus (malignant)

Ovarian teratoma Granulosa cell tumors Uterine leiomyoma Uterine fibroma Uterine myxosarcoma Uterine leiomyosarcoma

Mammary

Respiratory tract Benign Papillary Adenoma Nasal Adenocarcinoma Tumors of the skin Trichoepithelioms Papillomas Sebaceous adenoma Penile papillomas Lipoma Fibrosarcoma Fibroma Carcinoma Endocrine and Cardiovascular adrenocrotical adenoma Insulinoma Benign mixed tumors (myxoma) of the Cardiovascular system

Rhabdomyomatosis

Other tumors bile duct tumors undifferentiated carcinoma Lipoma fibrosarcoma histiocytic lymphosarcoma

adenocarcinoma, ductal origin Malignant mixed mammary tumor Adenoma bronchogenic origin

neurologic signs well differentiated mesenchymal components like bone cartilage and fat congenital condition characterized by vacuolation of myofibers and glycogen deposition

Rabbits Order

Lagomorpha

2 rows of upper incisors, one right behind the other in the upper jaw

Lab Rabbits descended from the European Orytolagus cuniculus

the adjacent cecum has around patch of Cecotrophy- re ingestion of lymhpoid tissue called Erythrocytes 6.5-7.5 um, Sacculus rotundus- spherical mucous coated "night feces"the cecal tonsil heterophils (9-15 um) thickwalled enlargement at high in protein and Vitamin B (lymphocytes and with acidophilic granules the ileocecal junction complex macrophages in the lamina propria and submucosa Hematuria may be caused by Calcium is absorbed in adenocarcinoma, Urine contains Calcium Urine may be pigmented due proportion to diet and is uterine polyps, carbonate crystals and triple to dietary porphyrins, elevated excreted in the urine episodic bleeding from Phosphate crystals urobilin (all non-pathologic) rather than bile endometrial venous aneurysms, cystitis, or polyps Hemoendothelial placentation, receiving antibodies through placenta

duplex uterus with 2 hors and 2 cervixes

Bones are fragile, and light comared to muscle mass

Right chambers of heart are thin walled and may contain post mortem clots with no contraction

DNA Viral Infections Non-enveloped Adenovirus Adenoviral enteritis Enveloped Papillomavirus

Virus was isolated form the associated with intestinal wall and GI significant increases in contents, spleen, kidney, and E coli lung

induced ovulators

Birthing is called Kindling

Appendix is the tip of the cecum

the length of the duodenum has Brunners glands

Benign in cottontails (Sylvilagus), but causes Papillomas with progression to Rabbit (Shope) Papillomatosis Squamous cell frequently on eyes and ears Carcinoma in Oryctolagus rabbits (but no infectious virus is produced)

Oral Papillomatosis

Rabbit oral papilloma virus

pedunculated masses on the Basophilic intranuclear ventral aspect of the tongue inclusions and regress spontaneously

Poxvirus

Myxomatosis (Leporipox)

Rabbit (Shope) fibromatosis (leporipox)

Rabbit Pox

hypertrophy and Proliferation of large stellate proliferation of Leporipoxvirus mesenchymal cells (myxoma endothelial cells , and (indistinguishable from cells) interspersed within a epithelium becomes vaccinia) homogenous matrix of mucoid hyperplastic or material degenerative related to Myxomaytosis benign self limiting disease in and Hare and Squirrel wildlife Fibroma viruses Papules on skin with necrosis and hemorrhage, oropharynx, respiratory tract, spleen, liver

Pockless form, hepatic necrosis, pleuritis, splenomegaly, lymphoid necrosis

intranuclear inclusions in the renal tubular epithelium

Legs and feet- Visceral metastasis in young animals, fibroblast proliferation with mononuclear and PMN infiltration

Polyoma virus

Rabbit kidney vacuolating virus

Parvovirus Lapine Parvovirus Herpesvirus

transient depression and anorexia with no mortality

transmissibel to European Rabbits (Orytolagus) and cottontails

intracytoplasmic inclusions in the affected epidermis only (not mesenchyme) and conjunctiva; Insect transmitted

Inclusions in the epidermis and mesenchyme

South american type and Californian type that causes lethal disease of myxomatosis in European rabbit (Orytolagus)

Lymphoproliferative disease, lymphoid hyperplasia to lymphosarcoma

Epstein Barr virus analog

Herpes Simplex

Experimental model for herpes simplex encephalitis

Non-suppurative meningoencephalitis with necrosis of neurons and prominent intrnuclear inclusion bodies in neurons and astroglial cells

Herpes-like viral infections

Hemorrhage, hydropericardium

necrosis in spleen, dermis, lungs, adrenald, Intranculear eosinophilic to amphophilic inclusions

Leporid Herpesvirus 1 (Herpes Sylvilagus)

RNA Viral Infections Calicivirus

Rabbit Hemorrhagic Disease

DIC thought to play arole

necrosis of hepatocytes with bloody nasal discharge, hepatic dissociation, pulmonary hemorrhage and crypt necrosis, edema, hepatomegaly, pulmonary edema, Fatal to Orytolagus, not Sylvilagus splenomegaly, perirenal hemorrhage, necrosis hemorrhage, serosal of lymphocytes, ecchymoses erythrophagocytosis in spleen

Coronavirus

Coronaviral enteritis

Pleural effusion disease and Cardiomyopathy

small and large intesitne, enterocyte necrosis, villous blunting, mucosal edema, inflammation lymphoid depletion of spleninc follicles, focal degenerative changes in the thymus, and Not a natural pathogen lymph nodes, proliferative changes in glomerular tufts and uveitis

Rotavirus Rotaviral enteritis

similar lesions to coronavirus

Miscellaneous Sendai virus Rabies Bacterial Infections

Upper respiratory tract following intestinal innoculation racoon variant rabies

myocardial degeneration and necrosis

Respiratory Bacterial Infections

Pasteurella multocida Serotype A and sometimes D

Bordatella bronchiseptica Cilia-Associated Respiratry Bacillus Enteritis Complex 5-12 week old rabbits Rotavirus Coronavirus

Clostridium

Snuffles, atrophic rhinitis, otitis media, conjunctivitis, bronchopneumonia, abscessation, genital infections, abortions,

chronic rhinitis- catarrhal to mucopurulent exudate, turbinate atrophy

Bronchopneumonia- cranioventral to acute necrotizing fibrinopurulent pyometra, salpingitis, Suppurative otitis bronchopneumonia; chronic perioophoritis, media, with squamous bronchitis with peribronchial necrotizing metritis// metaplasia of tympanic lymphocytic inflammation, alveolitis Acute septicemia, bulla lining with heterophils predominating, meningoencephalitis multinucleated giant cells, pleuritis

suppurative peribronchial and perivascular bronchopneumonia and cuffing interstitial pneumonia Asymptomatic usually

lymphoid hyperplasia

Multi-factorial

perfringens Type E

Iota toxin

typical findings for all: submucosal edema, hemorrhage, ulceration and fibrinous exudatenecrotizing typhlitis

most common

disruption of normal gut flora predisposes

difficile spiroforme

E coli

Enteropathogenic strains (attaching and effacing)

serosal ecchymoses, edema Small and large of the walls of the cecum and intestine: Rods and colon, edematous mesenteric cocci lining the villi, villi lymph nodes, prominent often blunted, lamina lymphoid tissues in Peyer's propria is edematous patches and sacculus and infiltrated by rotundus heterophils

damage to enterocytes, profuse diarrhea, dehydration and death

Enterohemorrhagic Strains (EHEC)

Lawsonia

Proloiferative enteritis/ histiocytic enteritis

o153, o145

cecal and colonic edema, serosal hemorrhage

sloughing of enterocytes, vasculitis, edema, heterophilsHemolytic uremic syndromefibrinous vasculitis in interlobular blood vessels, swelling of glomerular tufts with leukocytic infiltration, glomeruli had swelling and fibrin deposition in capillaries

histiocytes with Suppurative and erosive to abundant granular proliferative with hyperplasia cytoplasm and MNGC. Silver and PAS stains show of enterocytes lining crypts PAS positive granular apically located epithelial bacteria and villi with mononuclear material (degrading infiltration bacteria)

Salmonella Vibrio Coccidia thickened and edematous, Clostridium piliforme (Tyzzer's serosa- fibrin on cecum multifocal necrosis in liver and Disease) and colon myocardium, transmural necrosis in cecum and colon Klossiella pneumoniae Salmonella

rarely associated with disease, normal inhabitant S typhimurium and enteritidis

intracytoplasmic bacteria

DDX: listeriosis and staph (liver)

hemorrhagic enterotyphlitis

Vibrio Mucoid enteropathy

Synonyms: mucoid enteritis, bloat, hypoamylasemia

teeth grinding, cecal impaction, gelatinous mucus in colon

Stomach distended with fluid and gas.

acute fatal disease, focal hepatitis, ascites, death typically is in advanced enlarged mesenteric pregnancy lymph nodes

Newborns may develop systemic listeriosis, stunting, meningoencephalitis

Other Bacteria

Listeriosis

Staphylococcus aureus

Chronic suppurative lesions

skin, mammary gland, genital tract, conjunctiva, footpads, upper and lower respiratory tract.

Acute septicemic form

suckling kits, multifocal suppurative lesions in the skin, lung, kidney, spleen, heart, liver

straw colored fluid in the abdominal cavity. Miliary pale foci of suppurative hepatitis in liver. Placenta is thickened with friable surface ddx: Pasteurella, Listeria, and Tyzzers

Treponema paraluiscuniculi

Mastitis

swollen, red

Respiratory

mucopurulent rhinitis and localized bronchopneumonia and abscesses

Pododermatitis

sore hocks

Venereal spirotrichosis

vulva, prepuce, anal, muzzle, periorbital

ddx: Staph, Pasteurella, Streptococci

edema, erythema, papules at mucocutaneous junctions

Syphilitic lesions progress to ulceration and crusting; Microscopically- hyperplasia of epidermis, necrosis of epithelium, erosions, ulcerations, plasma cells, macrophages, heterophils,

Helicobacter

unknown significance focal caseation necrosis of liver spleen, cecum, Yersinia pseudotuberculosis LN and reproductive tract

Necrobacillosis

Schmorls Disease

Streptococcal septicemia

young rabbits Diplococcal Corynebacterium pyogenes cause ulcerative skin lesions

dermatitis secondary to moist lesions are suppurative skin, in dewlaps, excessive with erosion and environmental moisture, ulceration malocclusion, panting

Mycotic Infections

Dermatophytosis

Trichophyton metagrophytes

Aspergillus

pulmonary granulomas, well circumscribed, central coagulation necrosis

head and ears, paws, alopecia, crusting raised

hyperkeratosis, epidermal hyperplasia, folliculitis, mononuclear DDX: idiopathic molts during nest and building, Barbering polymorphonuclear cells

Pneumocystis carinii

Pulmonary edema, congestion of alveolar vessels, thickening and hypercellularity of septaw, mononuclear and PMNS

Parasitic Diseases

Coccidia

Intestinal

Heaptic

Encephalitozoon cuniculi

Cryptosporidium cuniculus Toxoplasma gondii Pinworm

Eimeria intestinalis, Eimeria flavescens,

Eimeria steidae

Obligate intracellular microsporidian parasite

"infectious motor paralysis" can infect mice, guinea pig, ssquirrel monkey, cat, dog

Kidney: Focal irregular depressed areasGranulomatous nephritis

Lung, liver, CNS also granulomatous lesipons

Phacoclastic uveitis and cataracts usually asymptomatic

occasional bluning of villi may have multiple foci of necrosis and granulomatous clinical disease is rare inflammation in lung, liver and spleen Passalurus ambiguus adults in cecum

Ingested sporulated Sexual life cycle causes oocysts release destruction of enterocytes and sporozoites invade cells of the lamina propria. enterocytes and Cecotrophy does not infect multiply (Shizonts) --> because the oocyst require Gametogeny --> sporulation at room temp overnight Oocysts Sporozoites invade Histo: Periportal duodenal mucosa and fibrosis, dilation of bile spread systemically, ducts, mixed migrate to liver via Liver: raised linear bosselated inflammation, mononuclear cells and areas, yellow to grey hyperplasia of bile invade bile duct circumcsribed areas, gall bladder epithelium with epitheliium where thickened and contains flocculent papillary projections schizogony begins--> material lined by reactive gametogeny--> oocysts epithelial cells released in to bile overlying collagenous ducts tissue stroma

Spores shed in urine, Usually subclinical in transplacental infection can occur, rabbits, and renal oral or respiratory transmission is lesions are incidental common. Spores travel via findings monocytes hematogenously, targets are lung, liver, kidney 1.5 x 2-5 um spores in epithelial cells, macrophages, or free in the interstitium

In chronic renal lesions there is fibrosis and collapse of the parenchyma

Bylisascaris procyonis

cerebrospinal disease

torticoolis, ataxia, circling, opisthotonus

Gross- Raised white nodules in subepicardial and subendocardial locations and liver serosa

Nematodirus Trichostrongylus Multiple or single white noduels, necrotic Taenia pisiformis (Cysticercus) centers with inflammation and fibrosis Psoroptes cuniclui

Obligate non burrowing mites

Cheyletiella parasitovorax

Dorsal trunk, scapula, ventral abdomen

Sarcoptes scabei

Proliferative and hyperkeratotic otitis externa with euxdation mostly oily

(Parakeratotic) hyperkeratosis, seborrhea Burrowing mites in the pruritis and self and hair loss, face, nose, lips, superficial epidermis mutilation is common feet, abdomen, external genitalia

Notoedres cati Listrophorus gibbus Aging and Miscellaneous Hair Chewing (Barbering)

Hatch Burn

patchy alopecia on face Boredom and low roughage and back, young group diets have been implicated housed rabbits Urine scalding of the perineum- hyperemic and excoriated with serous exudate

Physical injury Exfoliative Dermatosis and Sebaceous adenitis

Ulcerative Pododermatitis Prolapse of the deep gland of the third eyelid

histo- Hyperkeratosis, non-pruritic scaling interface dermatitis and dermatitis with patchy folliculitis, reduced sebaceous coalescing alopecia glands and perifollicular fibrosis

One case was associated with a thymoma

circumscribed ulcerative Poor sanitation, trauma, and staphylococcus is most area covered by wire cages are implicated frequently implicated granulation tissues may be due to laxity in the supporting connective tissues

Histo: Pyogranulomas/ eosinophilic granulomas; In CNS lesions are in the grey and white matter. Mostly in the brain stem and cerebellum. Malacia, astrogliosis, gitter cells

Nematode larvae have excretory columns and lateral alae

Vertebral fracture Tracheal injury following intubation

Site is usually lumbosacral L7 can lead to incontinence with hemorrhage around the psoas muscles Erosive to ulcerative tracheitis Insufficient dietary predisposing factors include roughage, poor gastric excessive grooming and hair motility, and sedentary chewing due to boredom lifestyle are more important

Gastric Trichobezoar (Hairball)

incidental findings

Gastic Pyloric Hypertrophy

Marked muscular hypertrophy with interference with gastric emptying

Intestinal Plasmacytosis

Marked plasma cell infiltration in the intestinal tract

usually asymptomatic, frequently in animals used for antibody production and cholesterol studies

Cardiomyopathy associated with Ketamine/Xylazine/ detomidine

Multifocal myocardial degeneration with interstitial fibrosis

Attributed to ischemia secondary to vasoconstriction with reduced coronary blood flow

Chronic Renal Failure Renal Amyloidosis Vitamin E deficiency Calcium and Vitamin D deficiency

Hypervitaminosis D

Hypo or Hyper Vitaminosis A

Pregnancy toxemia

Metastatic mineralization of the aorta sparing of the gloeruli Nutritional muscular dystrophy Osteomalacia, overgrowth

neonatal mortality and infertility

Medial degeneration In long bones there is and mineralization of depostion of basophilic major arteries, material (osteoblasts) on the glomerular tufts, tubular periosteal and endosteal BM surfaces Poor ceonception, congenital abnormalities, fetal reabsorbtions

Microencephaly, hydrocephalus, cleft palate

Mobilization of fat Obesity, hereditary, imparied deposits leads to blood flow, pituitary metabolic acidosis and dysfunction all predisposing ketosis with fatty liver factores

pale mineralized streaks in muscle

Lead Toxicosis

Myocardial degeneration, Anemia, tremors, and hepatic necrosis, renal tubular posterior ataxia degeneration, hemoglobin casts

Hereditary Disorders Autosomal recessive, Absence or underdevelopment of Enlargement of 1 or both eyes the outflow channels with corneal opacity with incomplete cleavage of the iridocorneal angles

Congenital Glaucoma (Buphthalmia)

New Zealand White Rabbits

Malocclusion

Autosomal recessive, the mandible is long in relation to the maxilla

overgrowth of premolar and molar teeth also occur (seen in animals with diet deficient in calcium and vitamin D)

Endometrial Venous Aneurysms

Persistent urogenital bleeding, clotted blood in uterus

Blood filled endometrial varices consisting of dilated thin walled veins

Neoplasms Uterine Adenocarcinoma

Lymphosarcoma

Most common Nodular frequently Cauliflower like surface spontaneous neoplasm multicentric enlargements of and central ulcerations in Oryctolagus cuniculus one or both uterine horns

Leukemia only occasionally occurs

Kidney and gastric In cottontail has been Liver is enlarged, pale, and mucosa most common associated with Herpesvirus swollen, spleen is large and lymph sites, confined to renal sylvilagus nodes large cortex

Stomach wall is thick with irregular plaques and mucosal ulceration

Thymoma

Serosal implantation and metastasis to the lung and liver

Aside from thymic involvement there may be variable lymphocytic 1 case of hypercalceima and infiltrates in the other exfoliative dermatitis organs like, lymph nodes, liver, heart, and lungs

Prolactin-producing Pituitary Adenomass with Associated Mammary Dysplasia

Swelling of 1 or more mammary glands with enlargement and discoloration of the teats, thinning of haircoat

Dilated cystic ducts lined by flattened cuboidal epithelium with papillary projections

Common Mice Strains Common Diseases C57BL/6 (B6)

Back ground strain, longevity

Hydrocephalus

Melanism- coat color, heart valves, splenic capsule , meninges

Hippocampal neurodegeneration Microphthalmia Anophthalmia cochlear degeneration- age related malocclusion barbering- with alopecia and Staph dermatitis Pulmonary proteinosis- aged epithelial hyalinosis amyloidosis- late onset lymphoma hemangiosarcoma pituitary adenoma

BALB/ c or cBy

Albino,Pugilistic males

Dystrophic epicardial mineralization myocardial degeneration auricular thrombosis corneal opacities conjunctivitis and blepharitis periorbital abscesses Hypocallosity (aplasia of corpus callosum) resistant to amyloidosis normal hepatic lipidosis lung adenomas lymphoma Harderian gland tumors adrenal adenomas Myoepitheliomas of salivary, preputial, and other exocrine glands

C3H/ He

Agouti, Blind (rd1 mutation)

corneal opacities Hearing loss focal myocardial and skeletal muscle mineralization myocardial degeneration alopecia areata (HeJ)

Murine Mammary tumor virus- induced mammary tumors hepatocellular tumors

129 mice

Embryonic stem cells; variation in coat color and behavior

Hypocallosity (aplasia of corpus callosum) Pulmonary proteinosis epithelial hyalinosis Megaesophagus conjunctivitis and blepharitis Testicular teratomas (embryonal carcinomas) lung tumors Harderian gland tumors Ovarian tumors hemangiosarcoma

FVB/ N

Swiss Mice, blind (rd1)

Siezures persistent mammary hyperplasia adenoma of prolactin secreting cells of anterior pituitary lung tumors pituitary adenoma Harderian gland tumors Liver tumors lymphoma pheochromocytoma

Outbred Swiss Mice

amyloidosis- late onset retinal degeneration lymphoma Pulmonary adenoma Liver tumors pituitary adenoma hemangiosarcoma