Diseases Of Lab Animals

Mice DNA Viral Infections Non-enveloped Adenovirus

DDX:

Mouse Adenovirus-1

Murine adenovirus A

Mouse Adenovirus-2

Murine adenovirus B

Replicate in nucelus; INIB

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

Enterotropic

Hemorrhagic encephalitis in susceptible thymic involution, necrosis of mice; Hemorrhagic enteritis, fatty liver, liver and spleen wasting disease

runting

Polyomavirus, cytomegalovirus

Intestinal epithelial are unique to Madv-2

Enveloped Herpesvirus Betaherpes

Mouse Cytomegalovirus

Murid Herpesviris -1

Mouse Thymic Virus (MTLV)

Murid Herpesvirus -3

Replicate in nucleus and cause cytomegalic inclusions with INIB and ICIB INIB

salivary glands

Thymus

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 Thymic necrosis, granuloma

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

INIB

Salivary gland tumors, kidneys, 40 other cell types

Multifocal necrosis and inflammation

INIB in vascular endothelium

replicates in intestinal capillary endothelium

liver, lung, brain, spleen

INIB in spleen mononuclear cells

Kidney, intestine, lymphoid tissue, liver

INIB, 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

Tumors of mammary gland, salivary gland, thymus, skin tumors, renal sarcoma, osteosarcoma, hemangiosarcoma, fibrosarcoma pulmonary vascular edema and hemorrhage

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

DDX: Polyoma virus of mouse, adenovirus, cytomegalovirus

Parvoviridae Mice Minute Virus (MVM) Mouse Parvovirus 1

similar to MVM, but infects mice of all ages

Ectromelia

Ectromelia virus (ECTV)

more pathogenic for hemorrhage, hematopoietic involution, hemopoietic tissue than MPV; renal papillary infarction Targets outer granular layer of cerebellum

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

Coronavirus

runts, wasting, vasculitis, glomerulonephriti Lymphocytic Choriomeningitis s, lymphocytic Virus infiltration in brain , liver, adrenal, kidney, lung

Lactate DehydrogenaseElevating Virus Infection (LDV)

Necrosis of T cell in lymhpoid tissue, Scattered neuronolysis with apoptosis generalized and perivasculitis, non-suppurative splenomegaly, leptomeningitis, myelitis, radiculitis lymphadenomeg aly

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

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; Enteritislymphocytes and vacuolation/ epizootic diarrhea, salmonella, Tyzzers, Reovirus; granulomatous serositis in IFN Demyelinating- Mouse encephalomyelitis virus, LDV, deficient mice Polyoma virus in immunodeficient mice

Paramyxoviridae

Pneumonia virus of mice (PVM)

Murine pneumovirus (MPV)

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

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

SCID mice have marked vacuolation and MEV or Theilovirus (ThV); Viral encephalitis attacks neurons and glia; neuronolysis, enlargement of affected neurons, in the Mouse encephalomyelitis virus Mouse poliovirus or Theiler's and neuronophagia, microgliosis, nonbrain stem and ventral horn of a spinal virus demyelination suppurative meningitis and perivasculitis cord.

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

Sendai Virus

Sendai Virus (SeV)

Infects respiratory epithelium and Type II pneumocytes

CD-8 Triggered apoptosis of infected cells

Picornaviridae

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

Murine norovirus (MNV-1)

Non-pathogenic, tropism for macrophages and dendritic cells, replicate in lung liver, and lymphoid organs in macrophages

Alveolitis, pulmonary edema, coagulation necrosis in liver, minimal inflammation, necrotizing splenitis, endothelial hypertrophy in STAT1 null mice

Multiofcal mononuclear hepatitis, interstitial pneumonia, pleuritis, peritonitis

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

Retroviridae

general info

Other autonomous retroelement flanked MuLV and by LTR's are: Intracisternal A particles MMTV's encode Non-autonomous retroelements must borrow reverse (IAP's), MusD elements, VL30 elements, LINE's are long interspersed retroelements make up 37% of the mouse genome, most their own reverse transriptase- they encode no proteins but are flanked by Most are methylated and glutathione tRNA primer binding sites nucleotide sequences and considered genetic parasites. These require transcription transcriptase and LTR's (early transposons (Etns), Short interspersed 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 are incorporated nuclear elements (SINES); Also there are numerous LTR's retroelements (MuERV's- include these lack LTR's into the genome with no internal reading frame MuERVC, MuRRS, MuRVY's) These are (provirus) mi Endogenous retroelements are mostly defective, they do represent mobile DNA that can re-integrate in other regions of the genome during cell division withour virion assembly and re-infection LTR's include enhancers, promotors, which dictate transcriptional acitivty and tissue MMTV- tropism for mammary tissue specificity Once in the viral genome they are called viral Acute transforming retroviruses have incorporate a host cell proto- oncogenes and such v-onc genes and are capable of oncogene that directly alters may be mutated transforming a cell quickly instead of cell division to increase their relying on random insertional pathogenicity, mutagenesis but also may be defective transmitted Re-integration into the somatic genome through milk, results in random insertional Exogenous and endogenous semen, saliva, mutagenesis and neoplasia follows etc integration near host proto-oncogenes insertional Mammary gland neoplasia, mutagenesis can be endogenous or exogenous and lymphocytotropic transforms transmitted in milk lymphocytes

Exogenous retroviruses are transmitted horizontally as conventional viruses LTR's encode superantigen gene (sag)

MuSV-sarcomavirus

MuLV

MMTV

Mouse lymphoma - B cell and arise in spleen.

Bacterial Infections Enteric Infections

Citrobacter rodentium

hyperplastic, catarrhal colitis; Induce dissolution of non-flagellated, species specific, brush border, bacterial colonization elicits intense requires direct contact, colonizes cecum Acquired immune response is 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 contracted thickended colon, erosion, including translocated intimin receptor severity formation similar multifocal hepatitis and splenitis (Tir) to attaching and effacing E coli (EPEC and EHEC)

Escherichia coli

Coliform typhlocolitis

Large intestinal hyperplastic lesions, thickended colon mucosa, mucosal hyperplasia

Clostridium piliforme

Tyzzer's Disease

red mucosa, inflammation, necrosis in mucosa and muscularis

Helicobacter hepaticus

Salmonella

Typhimurium Enteritidis

Chlamydiae

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

intracellular, in macrophages

obligate intracellular

Mycoplasma

Klebsiella

K oxytoca- suppurative female repro tract lesions

interrogans ser icterohemorrhagiae

pulmonary fibrinoid vasculitis, thrombosis, hemorrhage

renal tubular necrosis and interstitial nephritis

interrogans ser copenhageni

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

focal hepatic necrosis,

respiratory and genital tract disease ans sometimes arthritis

M neurolyitcum

Rolling disease

M Coccoides

transmitted by Polyplax serrata- louse

M hemomuris

typically infects rats

Lawsonia intracellularis

Pasteurella pneumotropica

Proteus mirabilis

multifocal liver necrosis with neutrophils, myocyte degneration, myocarditis, intracellular bacteria

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

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

old mice with suppurative endometritis, cystic endometrial hyperplasia, salpingitis, perioophoritis/ peritonitis (abscesses and adhesions)

M pulmonis

DDX: C rodentium, Helicobacter, Enterotropic MHV

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

Cilia-Associated Respiratory Bacillus

Leptospira

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

perineal fecal staining

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

rats hamsters, Proloferative enteritis, typhlitis guinea pigs and or colitis rabits Conjunctivitis, panophthalmitis, dacryoadenitis, Respiratory, enteric and periorbital Necrotizing dermatitis, mastitis, metritis, genital tracts abscressation, UTI, abortions rhinitis, otitis, cervical lymphadenitis splenomegaly, multifocal hepatic Suppurative pyelonephritis Fibrinous peritonitis lesions in SCID mice

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

septic thrombi in vessels

Conjunctivitis, nasal discharge

subcutaenous edema and sudden death

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

Suppurative embolic nephritis, polyarthritis, osteomyelitis

Rat Bite Fever- potentially fatal zoonotic

Non-Type A, type B and Type D C diff toxin A and B

large or small intestine

necrotizing and hyperplastic changes

generalized lymphoid apoptosis and renal tubular vacuolation

Clostridium difficile Corynebacterium kutscheri

Pneumonia, caseous necrosis

liver, kidney, lungs, lymph nodes

hematogenous

conjunctivitis, thrombosis, gram positive bacilli

Corynebacterium bovis

Hyperkeratosis

lipophilic and grows in keratin

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

Corynebacterium spp

Conjunctivitis

Staphylococci

Conjunctivitis

Pseudomonas aeruginosa

ulcerative lymphangitis, vasculitis, thrombosis, necrosis, hemorrhage

DDX: Corynebacterium kutscheri, Enterobacter cloacae

Burkholderia gladioli

Clostridium perfringens

Staphylococci

Streptococci

Streptococcus

Strep agalactiae

Strep equisimilis

Enterotoccus

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

hemolysins, nucleases, exfoliative exotoxins, leukocidin, proteases, Necrotizing dermatitis Enterotoxins and Toxic shock syndrome lipases, toxin-1 hyaluronidase, collagenase Gram pos bacteria Chronic disease can cause surrounded by Lymphadenitis multisystemic amyloidosis and splendore splenomegaly hoeppli material (botryomycosis) Group AGroup B- Meningoencephalitis, bacteremia, Lancefield groups A, B, C, G ependymitits, periventriculitis, (from cervical nose), pyelonephritis, septicemia lymphadenitis DBA/2 mice with pyelonephritis and subsequent bacteriemia with Group B disseminated lesions to the heart, kidneys, spleen, liver, uterus, thorax subcutaneous, hepatic, and Group C abdominal abscesses Necrotizing dermatitis with Group G vasculitis and thrombosis with Pseudomonas Lancefield group D can cause enterococcus durans and faecalis bacteremia in SCID mice

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

Mycobacteria M. avium intracellulare

asymptomatic with subpleural granulomas

DDX: M pulmonis, Corynebacterium kutscheri, Freunds adjuvant lesions

Mycotic Infections Dermatophytosis

Cuplike crusts on head ears, Trichophyton mentagrophytes face, tail, extremities

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

Actinomyces Gastric

Defective NADPH oxidase Defective NADPH oxidase

Chronic granulomatous disease Trichosporon beigelii

Paecilomyces, Aspergillus, Rhizopus, Candida

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

adhere to type 1 pneumocytes

Asci (cysts) are carriers are asymptomatic and disease Interstitial pneumonia with proteinaceous also present and presents in immunosuppressed mice exudate in the alveolar lumina, contain 8 causing pneumonia thickening of alveolar septa ascospores

Acariasis

fur mites

3-5 um cysts, irregularly flattened

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

Parasitic disease Ectoparasites

Follicle Mites

Demodex musculi Psorergates

rare

Ornithonyssus bacoti

tropical rat mite

blood sucking intense pruritis

Pediculosis

Louse Polyplax serrata

Myobia, Radfordia, Mycoptes, Tichoecius

epidermal hyperplasia and hyperkeratosis

Myobia musculi

hypersensitivity

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

heavy infestations can result in anemia

Protozoal endoparasites Eimeria

vermiformis, falciformis, papillata, ferrisi

Cryptosporidium

muris

gastric mucosa, relatively non-pathogenic

Cryptosporidium

parvum

small intestine, marginally pathogenic

Giardia

muris

lumen of duodenum

Spironucleus

muris

(formerly hexamita)

Toxoplasma

gondii

rare in lab mice

Sarcocystis

muris

rare in lab mice

Klossiella

muris

Encephalitozoon cuniculi

microsporidiosis (more like fungi)

renal coccidiosis granulomatous hepatitis, interstitial nephritis, meningoencephalitis

enteritis secondary to viral infections poor hair coat, distention commensal inghabitant of intestine cats definitive hosts cats definitive hosts

cholangiohepatitis with focal hepatic necrosis, peribiliary fibrosis

crypts and intervillous spaces are distended, lymphocytes and plasma cells

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

adults live in cats

larval form in stobilocercus (cysticercus fasciolaris)

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

AA

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

cysticerci in lamina propria nana also capable of superinfections via and threadlike adults adults in direct ife cycles lumen

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

Soft Tissue Calcification BALB/c

Epicardial mineralization with fibrosis of the RV free wall

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

C3H

DBA mice

Acidophilic Macrophage Pneumonia/ Epithelial hyalinosis

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

Reye's like Syndrome

foci of degeneration and Skeletal myofiber mineralization throughout LV mineralization myocardium and IVS dystophic mineralization in the aorta, testes, epicardial and myocardial tongue, muscle, mineralization cornea, kidney, stomach, small intestine, ovary

hepatoencephalopathy and fatty degeneration of the viscera

part of the syndrome

B6, 129

in the tongue can form inflammatory polyps

cytoplasm packed with needle to rhomboid shaped crystals

Any disease that impairs normal pulmonary clearance can predispose to AMP

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

mitochondrial anticedent viral infections and swelling with aspirin therapy are 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 Penis self mutilation

DBA, Swiss, BALB/c

Bar-mouthing, jumping, circling, somersaulting, routetracing tritrichotillomania B6

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

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

Siezures

DBA/2, SJL, LP

audiogenic siezures

Hypocallosity

aplasia of corpus callosum

Hydrocephalus

C57Bl

Vacuolation of White Matter

fixation artifact

domes, runted and dehydrated

hairloss increases with age

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

predispose to necrotizing dermatitis hyperkeratosis and glabrous associated with MHV skin neuronal necrosis of cortex, ejaculation with retention of urethral hippocampus, centrilobular coagulation necrosis of liver plugs resulting on obstructive uropathy thalamus, generalized gliosis reduced neuronal proliferation, defects in ependyma, lamination of cortex, microencephaly

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

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

Megaesophagus 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

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 Alveolar lipoproteinosis

Alveolar hemorrhage

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

neutrophilic or mononuclear

usually incidental

left side usually

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

cholesterol or hemoglobin crystals

progressive intraalveolar may overlap with accumulation of granular pale hypertrophy and vacuolation acidophilic eosinophilic phospholipid of Type II pneumocytes macrophage (surfactant) pneumonia extravasation of blood into alveolar spaces is common agonal finding

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

obstructive uropathy

cellulitis, paraphimosis, hydronephrosis

prostatitis, DDX- agonal release of coagulum from cystitis, urethritis, accessory sex glands balanoposthitis

Amyloidosis Membranoproliferative glomerulonephritis LCMV and retroviruses

chronic progressive nephropathy (resembles the disease in Rats)

non-specific basement membrane thickening (glomerular hyalinosis)

Hydronephrosis

usually incidentsl

renal Infarction Polycystic disesae Renal tubular hyaline bodies

BALB/c Hyaline eosinophilic bodies in cytoplasm of tubules

Inclusion body nephritis

Homogenous intranuclear eosinophilic inclusions

Chloroform Toxicity

Renal tubular necrosis

glomerular sclerosis, tubular degeneration, regeneration, interstitial inflammation, dilated tubules with protein rich fluid DDX- renal papillary necrosis due to amyloidosis

association with histiocytic sarcomas negative for adjacent interstitial infiltrates Polyoma virus, K of lymphocytes virus, adenovirus

mineralization

Males > Females; castration eliminates sensitivity

DBA and C3H mice

NSAID nephropathy

Tubular degeneration with mineralization

may progress to chronic nephropathy

Pale kidneys with irregular outlines, tubular degeneration and atrophy in cortex and medulla

Mucometra/hydrometra

BALB/c, B6, DBA

abdominal distension

one or both uterine horns dilated

Cystic endometrial hyperplasia

aged female mice

may be associated with secondary bacterial pyometras

Mammary Hyperplasia

glandular invasion of the myometrium virgin female FVB/N

Bulbourethral glands cysts

Small pear shaped

Adenomyosis

oftne extends to serosa

some have congenital imperforate vagina

DDX- Pyometra, retained fetuses, neoplasia

Cystic glands present as unilateral or bilateral swellings of the perineum

may be suppurative- Staph aureus, Pasteurella pneumotropica

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

DDX- neoplasia

secretions are at the base of penis and part of copulatory embedded in skeletal muscle plug

Seminal Vesicular Dilatation and atrophy Pseudocanalization and Megalokaryocytosis of male reproductive epithelium

Fibro-osseus lesions in Aged sternebrae, vertebrae, femurs mice

aged female B6C3F1

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

small cell

multisystemic, lung , kidney, often with leukemic phase

spleninc marginal zone

multifocal in spleen

Diffuse large B cell

Resemble follicular lymphomas

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

Burkitt-lymphoma Burkitt-like lymphoma Plasma cell

T cell

Precursor T cell Mature T cell

B natural killer cell Cd4-/ Cd8-, CD3+ Small cell

Lymphoblastic . Not Herpes virus associated Plasmacytoma Extraosseus plasmacytoma anaplastic plasmacytoma

enlarged thymuses

medium sized and uniform with scant cytoplasm

Splenomegaly, lymphadenomegaly, not Thymic associated

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

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

spleens are enlarged; cells have abundant cytoplasm

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

can be histiocyte associated

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

Cribriform Papillary

Solid Squamous Fibroadenoma Adenomyoepithelioma Adenosquamous NOS

composed of glands multicentric and multinodular, well glandular structures with small MMTV's are either exogenous circumscribed, lumina (MMTV) or endogenous (low grade) pulmonary metastasis is common Sheets or nests forming lumina with round punched out spaces fingerlike projections of epithelium covering a central vascular core solid sheets of epithelium with little or no glandular differentiation 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

originate from Type II A strain is highly susceptible enhanced with viral infections pneumocytes or due to a mutated K-ras allele such as Sendai its precursor common to Clara cells

Primary pulmonary adenocarcinoma Papilloma Squamous cell carcinoma Adenosquamous carcinoma neuroendocrine carcinoma Hepatocellular neoplasia

closely packed cuboidal to lining Cells are non ciliated and may remnants of alveolar septa with sparse DDX- focal alveoalr epithelial cell hyperplasia (older mice) have mucinous differentiation collagenous stroma Sub-pleural masses +/- invasion and seeding of visceral and parietal pleura

Hepatocellular adenomas and carcinomas

Aged males > females

A and DBA strains

Hepatoblastoma

organoid structures arranged around vascular channels

or forming rows and rosettes

papillary cystadenomas or solid adenomas

slow growing, appear late in life

protrusion of the eye with porphyrin staining

Adenocarcinomas

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

Myoepitheliomas

BALB/c and BALB/cBy

Helicobacter spp

columnar cells

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

well circumscribed, unencapsulated, anisokaryosis, karyomegaly, cytomegaly

Cholangioma Cholangiocarcinoma hemangioma hemangiosarcoma Histiocytic sarcoma Ito cell tumors (rare) Harderian gland tumors

Reproductive Neoplasms Female Papillary cystadenomas

Females > Males

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

well differentiated epithelial cells with vacuolated cytoplasm

Arise from Cystic chambers containing serous fluid submaxillary and may also be associated with mammary, (necrosis)/ large pleiomorphic spindle parotid salivary preputial, and Harderian glands cells with epithelial and mesenchymal glands features

metastasis to lungs, myeloid hyperplasia of bone marrow and spleen

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

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

Parvoviridae

Group 1

Group 2 Group 3

scrotal hemorrhage with peritesticular Kilhams rat virus (RV) fibrinous exudation, necrosis and infarction due to thrombosis

Splenomegaly, liver necrosis, encephalomalacia

INIB in hepatocytes, cerebrallar hyoplasia, may have reproductive endothelial cells and hepatitis, and jaundice disorders bile duct epithelium in neonates

DDX- pseudomoniasis septicemia, Mycoplasma pulmonis, trauma

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

may be cowpox virus

RNA Virus Coronavirus

Bunyaviridae

HPS Rat Respiratory Virus

Perivascular lymphohistiocytic interstitial alveolitis

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,

Humans- pulmonary capillary leakage some neutrophils and type II pneumocyte hyperplasia

DDX: Sendai, and Pneumonia virus of Mice

Paramyxoviridae Pneumonia virus of Mice

mice, rats, hamsters, guinea pigs, gerbils

Non-suppurative vasculitis and interstitial alveolitis with necrosis

Perivascular infiltrates, hyperplasia of BALT, perivasculitis

DDX: Sendai, Rat Respiratory virus, Rat coronavirus

Sendai Virus

Parainfluenza 1

Mice, rat, hamster

MHG RCaV

neurologic

respiratory epithelial necrosis

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

Maybe concurrent infection with Rat coronavirus, Mycoplasma

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

uncommon

important in guinea pigs and Rabbits

Suppurative Rhinitis

Bronchopneumonia with peribronchial lymphoid hyperplasia

filamentous argyrophilic bacillus

similar to primary mycoplasma infections

Chronic suppurative bronchitis and bronchiolitis

Peribronchial cuffing with lymphocytes and use Warthin Starry stain plasma cells

M pulmonis

Catarrhal and suppurative bronchopneumonia

Intestine

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

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

Haemophilus Murine Respiratory Mycoplasmosis

Pasteurella pneumotropica

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 Enterococcus faeciumdurans-2

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 Enteropathy in Infant abdominal distention Rats

Erysipelas

Fibrinopurulent polyarthritis, myocarditis, endocarditis

Mycoplasma haemomuris

formerly hemobartonella muris

transmitted by Polyplax spinulosa

Klebsiella pneumonia

Opportunistic

abscesses in cervical, inguinal, mesenteric lymph nodes and kidney

Fibrinous pleuritis

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

hyperplasia of epidermis,

bacteria in crust

DDX: Corynebacterium, Salmonella, Pseudomonas, Pasteurellosis gram postiive bacteria on villus tips of small intestine

Natural infections are inapparent

subclinical with no lesions Septicemia, Pseudomonas pulmonary edema, Endocarditis, vasculitis Lung spleen, kidneys aeruginosa splenomegaly, with thrombosis visceral ecchymoses Zoonotic, Streptobacillus maculopapular rash, Rat Bite Fever moniliformis fever, headache, polyarthritis E. coli, Klebsiella, Pseudomonas, Bacterial Pyelonephritis/ Corynebacterium, cystitis, proctatitis Nephritis Streptococcus, Enterococcus, Proteus Pulmonary Lesions of Unknown Etiology Leptospira

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

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

DDX: Corynebacterium kutscheri, Pasteurella pneumotropica, Salmonellosis, Mycoplasma

Pneumocystis carinii/ wakefieldii

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

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

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

R. Microstoma Hymenolepis diminuta Cysticercus fasciolaris is the larval stage

eggs ingested--> migrate through bowel--> encyst in liver of mice (cysticercosis)

Cat eats mouse and becomes Taenia taeniaformis

Sarcomas may develop around the cysticerci

Chronic Progressive Nephropathy/ Nephrosis

Males> females

pitted and irregular with pallor

chronic glomerulopathy/ glomerulosclerosis/ interstitial fibrosis

proteinuria/casts/ PAS positive hyaline droplets

Nephrocalcinosis

various dietary factors

Taenia taeniaformis Aging and Degenerative Disorders

Hydronephrosis

Brown Norway Ratautosomal polygenetic disorder Gunn Rat_ autosomal dominant

secondary changes: Hyperparathyroidism, mineralization

Nephrotic syndromehypercholesterolemia, hypoproteinemia, BUN/CT

S-D: highly heritable

Urinary Calculi

don’t confuse with agonal copulatory plugs

Hematuria/ renal Papillary Hyperplasia

associated with hydronephrosis

Myocardial Degeneration and Necrosis

Polyarteritis

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

Liver changes

Polyploidy, megalokarya, binuclear hepatocytes, intranuclear cytoplasmic invaginations

vacuolation of the cytoplasm. Fragmentation of ventricular hypertrophy sarcoplasm, loss of and pale streaks cross striations, mono-nuclear cell inflammation

interstitial fibrosis with proliferation of fibrous tissue

Mesenteric vessels, microscopic lesions tortuous and thickened 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

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

Bile ductular Focal sinusoidal proliferation, lined by dilatation and peliosis, atrophic epithelium, either spontaneous or surrounded by drug induced collagenous tissue

Miscellaneous Disorders 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

Dehydration

accompanied by porphyrin staining around the eyes (sign of stress)

Epidermal hyperplasia with orthokeratotic and parakeratotis hyperkeratosis

Dilated and thrombosed vessels, necross, hemorrhage

Retinal Degeneration

Corneal lesions

Bedding

albino rats are predisposed due to unpigmented uveal tracts

progressive reduction Advanced disease has of photoreceptor marked depletion and nuclei in the outer alteration of the retinal nuclear layer of the layers with cataract central retina formation

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

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

Cutaneous Lymphoma (mycosis fungoides)

Histiocytic Sarcoma

Splenomegaly with DDX- Lymphoma and erythrophagocytosis histiocytic sarcoma

anemia and icterus

Splenomegaly, enlarged lymph nodes, hepatomegaly epitheliotropic/ circumscribed medium to large size, erythematous T cell lymphocytes plaques pregressing and dissociated to ulceration adjacent epidermal cells

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

may consist of primarily connective tissue, or epithelial cells predominate

Pituitary gland tumors majority/ SD/ Wistar Chromophobe adenoma rats

Prolactin secreting IHC required for tumors most common; positive identification may contribute to mammary tumors

pars distalis

Testicular Tumors Interstitial cell tumor

F344 older males

lobulated light yellow`

Mesothelioma

F344

Tunica vaginalis of testis

also have smaller polyhedral to elongated cells with cells with granular hyperchromatic nuclei vacuolated cytoplasm and scant cytoplasm

concurrent hypercalcemia

Holocrine gland at the Zymbals Gland Tumors base of the ear Other

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

Missing incisor teeth

H-1: necrosis and inflammation of dental pulp with mononuclear leukocytic infiltration of the dental lamina and osteoclasiss of alveolar bone

New Strain: enamel hypoplasia, periodontitis, Multifocal cerebellar and cerebral suppuration and hemorrhage and thrombosis with mineralization, transmural hemorrhage hemorrhage in dental pulp

Hamster Polyoma Virus

keratinizing skin tumors of hair follicle origin

Non glabrous skin- keratinizing can be papilloma like follicular structures reminiscent of trichoepitheliomas

Enveloped Herpesvirus Salivary and Lacrimal glands

cytomegaly with INIB and ICIB

Parvoviridae

Polyomavirus Transmissible Lymphoma

Lymphoma

Abdominal masses, large lymph nodes

liver, kidney, thymus

RNA Virus Arenaviral infection Paramyxovirus Sendai virus

Bacteria GRAM (-) Enteric

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

Campylobacter jejuni

co infection with Lawsonia

Zoonotic 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

Lawsonia intracellularis

Runted and emaciated hamsters

soiling of perineum

Tyzzer's

Clostridium Piliforme

intracellular

Hepatic necrosis, Ileum , cecum, colon

focal granulomatous myocarditis with conspicuous bulging nodules

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

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

neutrophilic inflammation

focal necrosis fo liver, with neutrophils

DDX: Clostridium, Lawsonia, Salmonella

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

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

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 Cecal mucosal hypertrophy of ceca ar congested hyperplasia of enterocytes Unknown etiology contracted and opaque lining the crypts Gram (+) Respiratory Non-Antibiotic-associated

Clostridium difficile

Corynebacterium kutscheri

local granulomatous and suppurative lesions

oral cavity, lymph nodes

Streptococcus pseumoniae S. agalactia Gram (-) Francisella tularensis Leptospira ballum

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

high fat diet

Yersinia pseudotuberculosis Pasteurella pseumotropica and others Mycoplasma pulmonis Mastitis Strep P pneumotropica E coli

Chronic emaciation with intermittent diarrhea

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

URI, Otitis, Bronchopneumonia

Cutaneous and cervical abscess Actinomyces bovis Staphylococcus aureus Streptococcus Pasteurella pneumotropica

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

more common

Trichosomoides

nasalis

Tapeworms Cysticercus Rodentolepis Hymenolepis

fasciolaris microstoma Nana diminuta

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

dogs and cats

Nutritional and Metabolic Disorders Spontaneous Hemorrhagic Necrosis (SHN) of the CNS of fetal hamsters

Stillborn or weak

Diabetes Mellitus

Recessive in Chinese hamsters

Prosencephalon: Symmetrical, subependymal, vascular degeneration, with edema and hemorrhage Weight loss, glucose intolerance, hyperglycemia, polyuria, polydypsia, hypoinsulinemia, ketonuria

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

high temps, low water may stimulate estivation

Hamster Glomerulopathy (arteriolar Nephrosclerosis)young animals

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

Histo: Thickening of BM with eosinophilic material

may be concurrent amyloid in advanced lesions

Amyloidosis (older animals)

Females > Males

Hamster female protein similar to Amyloid P

DDX: trauma and cannibalism

stenosis of cerebral aqueduct

Cannibalism Hibernation and Estivation

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

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

Vitamin E related/ deficiency

Atrial Thrombosis

Left auricle and atrium

often associated with amyloidosis

bilateral ventricle hypertrophy is common

focla to diffuse myocardial degeneration; medial degeneration and calcification of coronary arteries

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 nodular hepatocellular Bile Ductular Hyperplasia/ nodularity, periportal degeneration, necrosis, and Hepatic cirrhosis fibrosis, bile duct mixed leukocyte infiltration proliferation Alveolar Histiocytosis Fibrinoid degeneration of arterioles

Neoplasia Lymphoma Cutaneous Lymphoma resmbling mycosis fungioides Adrenocortical adenomas

Polyoma virus or spontaneous epidermotropic

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

Gerbils Virus Reovirus type 3

degenerative lesions in pancreas and focal necrotic lesions in the CNS

Bacterial Infections Tyzzer's Disease

Antibiotic associated enterocolitis Citrobacter rodentium Salmonella

Staphylococcal dermatitis

Nasal Dermatitis

Bordetella bronchiseptica Ciliary Associated Respiratory Bacillus

Leptospirosis

Helicobacter pylori Parasitic Diseases Demodex Giardia Pinworms Tapeworms Genetic Disease

Clostridium piliforme

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

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

following Amoxycillin and Metronidazole bloody diarrhea, thickening of goblet cell hyperplasia the colon and rectum typhimurium diarrhea, dehydration high mortality testicular enlargement, focal hepatitis, splenic necrosis, pyogranulomatous Group D suppurative orchitis, leptomeningitis interstitial pneumonia Histo- suppurative gross- moist dermatitis of dermatitis with Staph aureus face, nose, feet, legs, ventral acanthosis and abdomen hyperkeratosis porphyrin containing lacrymal secretions S Aureus and S xylosus dermatitis and alopecia have been an important contributing factor older animals are resistant, younger animals can have severe mortality

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

Clostridium difficile

asymptomatic 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

Upper small intestine Dentostomella translucida Rodentolepis nana

no clinical problems

not natural infection

may become ulcerative

diffuse suppurative encephalitis

DDX: Cl. Difficile, salmonella

Epilepsy

no histopathologic lesions

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

Lead Toxicity

Amyloidosis

Obesity and diabetes

Hyperadrenocorticism/Cardiov ascular disease Age related disease Focal myocardial degeneration

Chronic glomerulopathy

Aural cholesteatoma

Direct neuromuscular blocking by inhibition of acetylcholine release Chronic progressive nephropathy with acid Lipofuscin pigment granules fast intrnuclear in hepatocytes and Kupffer inclusions in renal cells proximal tubular epithelium filariid worm liver, spleen, lymph nodes

microcytic hypochromic anemia with basophilic stippling

DDX: Age related glomerulonephropathy, and erythrocytic basophilic stippling

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

only bred animala

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

necrosis and fibrosis 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

head tilt and keratin plugs in external ear canal

focal myocardial necrosis and fibrosis

Cystic ovaries

Ocular proptosis Neoplasms Mongolian gerbils

Other species

Helicobacter pylori

ovulation and corpus luteum formation continue protrusion of the nictitating membrane and conjunctiva with bulbar proptosis 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 adrenocortical tumors primary ovarian tumors Gastric carcinoma

Guinea Pigs Kurloff cells

Pulmonary arterial medial thickening Adventitial lymphocytes in pulmonary vesels Osseous metaplasia Thymus

Cardiac glycogenosis (Rhabdomyomatosis)

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

NK counterpart

normal normal in lungs degenerate thymocytes near Hassals corpuscles incidental degenerative condition and congenital tissue malformation with blastemoid features

lamellar bone with varying degrees of calcification

not significant

pale pink poorly delineated foci or streaks mostly in left ventricle

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

Arenavirus

Lymphocytic Choriomeningitis (LCM)

humans, primates, mice, rats, guinea pigs

focal hepatic necrosis and mortality

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

Karyomegaly and intranuclear and intracytoplasmic inclusions

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

DDX: Parainfluenza, cytomegalovirus, bacteria (bordatella)

Coronavirus-like Infection

Parainfluenza-3 (PI-3)

Paramyxovirus

Picornavirus

Typical lesions and disease interstitial pneumonia and alveolitis with pulmonary congestion and hemorrhage, relative sparing of airways Pneumonia virus of mice Sendai virus Murine Encephalomyelitis Virus strain GDVII Murine Poliovirus

Lameness

Bacterial Infections Enteric Infection Antibiotic Associated Dysbacteriosis (antibiotic toxicity)

Clostridial disease

Spontaneous Clostridial Enterotyphlitis

Clostridium perfringens Type A Clostridium piliforme C difficile

Tyzzer's Disease

Clostridium piliforme

Adenomatous Intestinal Hyperplasia

Lawsonia intracellularis

Salmonella

typhimurium

Clostridium difficile

cecum atonic and dilated hyperplasia of the with fluid and gas, mucosa with enterotoxin recovered mucosa is hemorrhagic mononuclear cell and edematous infiltration on the LP

necrosis of epithelium

organisms in enterocytes intracellular bacteria in enterocytes multifocal pale foci in liver and spleen

necrotizing ileitis and typhlitis, frequently transmural

necrotizing fibrinous enteritis, colitis

enteritidis Pseudotuberculosis

Yersinia pseudotuberculosis

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

Respiratory Infection Bordetella bronchiseptica

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

Guinea pig Inclusion Conjunctivitis

Chlamydophila caviae (formerly Chlamydia psittaci)

pleuritis, typanitis, chronic suppurative bronchopneumonia, heterophilic, obliteration of normal architecture red conjunctiva, purulent exudate, sloughed epithelium, intracytoplasmic inclusioins and bacteria

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

granulomatous hepatitis, splenitis, lymphadenitis

Citrobacter fruendii

Klebsiella

Pseudomonas aeruginosa Streptobacillus moniliformis Staphylococcus

Staphylococcus dermatitis

pneumonia, pleuritis, enteritis septicemia, necrotizing bronchopneumonia, pleuritis, pericarditis, peritonitis, splenic hyperplasia Pulmonary botryomycosis cervical lymphadenitis, pyogranulomatous bronchopneumonia Ulcerative pododermatitis (bumblefoot) erythema, hairloss, scabs, ventral abdomen and extrematies

sulfur granules

secondary to trauma, poor sanitation

plantar surface is swollen and painful with necrosis

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

epidermal cleavage, parakeratosis

Streptococcus

zooepidemicus group C

suppurative lymphadenitis

abrasions in oral mucosa

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

Diplococcal (pneumococcal) infection

S. pneumoniae

no toxins, just resistant to phagocytosis

fibrinopurulent pleuritis, pericarditis, peritonitis

bronchopneumonia with fibrin

Bacterial Syndromes Otitis media

Bacterial Mastitis

Bacterial Conjunctivitis

S pneumonia S zooepidemicus Bordetella Pseudomonas E coli Klebsiella Strep zooepidemicus Chlamydia Strep zooepidemicus Staph aureus Pasteurella multocida

Mycotic infections Dermatophytosis

Trichophyton mentagrophytes Microsporum canis

Parasitic Diseases Ectoparasites

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

ddx: Strep, Bordetella,

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

Helminth

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

Klossiella cobayae

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

Encephalitozoon cuniculi (microsporidiosis)

granulomatous encephalitis, interstitial nephritis

Toxoplasma

asymptomatic

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

hepatitis, pneumonia, myocardial cysts, CNS cysts

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

Necrotizing myopathy

periarticular hemorrhage

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

hemosiderin laden macrophages in lamina propria of intestine

increased susceptibility to streptococcus pneumoniae (impaired macrophage migration and heterophil phagocytosis)

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

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

Metastatic Calcification

> 1 year old

Pregnancy Toxemia (Hepatic lipidosis with ketosis)

Fasting or Metabolic Form Circulatory or Toxic form (preecclampsia)

soft tissues around the elbows and ribs

lung, trachea, heart, aorta, liver, kidney, stomach, uterus, sclera end of pregnancy

acidosis, ketosis, proteinuria, ketonuria, low urine pH (acidosis)

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

uteroplacental ischemia due to compression of the aorta

low magnesium and high phosphorus(high Ca and P diets interfere with Mg absorption) lowblood glucose, ketosis, hyperlipidemia placental necrosis, hemorrhage, ketosis, and death, periportal liver necrosis, leukocyte, nephrosis,

ddx: barbering, pediculosis, dermatophyte

Gastric dilatation and vovlulus Cecal torsion Intestinal hemosiderosis Focal Hepatic necrosis

Chronic Idiopathic Cholangiofibrosis

Liver contusions Foreign body pneumonia (Pneumoconiosis) Adjuvant associated pulmonary granulomas Behavior

lamina propria Subcapsular Periportal fibrosis, hepatocyte degeneration and interstitial fibrosis, proliferation of cholangioles traumatic fractures aspirated food or bedding

considered terminal

ddx: Tyzzer's

granulomatous bronchiolitis, or pneumonia

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

Diseases of Aging Segmental Nephrosclerosis

irregular pitted granular cortices

Cystitis and urolithiasis

Fecal contaminants such as E coli

pale linear streaks extend down into the cortex thick bladder mucosa, congestion intraluminal hemorrhage, mononuclear leukocytes, fibroblast proliferation, urinary calculi

interstitial fibrosis, tubular dilatation

interstitial lymhpocytes

Ovarian cysts

Fatty infiltration of pancreas

rete ovarii- large fluid filled cysts on the surface (cysts are continous with follicles and mesovarium) large areas of adipose tissue between normal panreatic acini

cystic endometrial hyperplasia, mucometra, endometritis, fibroleiomyomas

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

Cavian Leukemia

Reproductive tract Ovary Uterus (benign) Uterus (malignant)

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, 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

adenocarcinoma, ductal origin Malignant mixed mammary tumor Adenoma bronchogenic origin

adrenocrotical adenoma Insulinoma Benign mixed tumors (myxoma) of the Cardiovascular system

Rhabdomyomatosis Other tumors bile duct tumors undifferentiated carcinoma Lipoma fibrosarcoma histiocytic lymphosarcoma

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

Rabbits Order

Lagomorpha

Cecotrophy- re ingestion of mucous coated "night feces"high in protein and Vitamin B complex

Erythrocytes 6.5-7.5 um, heterophils (9-15 um) with acidophilic granules

Lab Rabbits 2 rows of upper incisors, one descended from the right behind the other in the European Orytolagus upper jaw cuniculus the adjacent cecum has around patch of lymhpoid tissue called Sacculus rotundus- spherical the cecal tonsil thickwalled enlargement at (lymphocytes and the ileocecal junction macrophages in the lamina propria and submucosa

Hematuria may be caused by Calcium is absorbed in Urine may be pigmented due adenocarcinoma, Urine contains Calcium proportion to diet and is to dietary porphyrins, uterine polyps, carbonate crystals and triple excreted in the urine elevated urobilin (all non- episodic bleeding from Phosphate crystals rather than bile pathologic) endometrial venous aneurysms, cystitis, or polyps Hemoendothelial placentation, duplex uterus with 2 receiving antibodies through hors and 2 cervixes placenta 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

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

Enveloped Papillomavirus 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)

induced ovulators

Birthing is called Kindling

Appendix is the tip of the cecum

the length of the duodenum has Brunners glands

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 hyperplastic or mucoid 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

Polyoma virus Rabbit kidney vacuolating virus

Legs and feet- Visceral intranuclear inclusions metastasis in young animals, in the renal tubular fibroblast proliferation with epithelium mononuclear and PMN infiltration

Parvovirus Lapine Parvovirus

transient depression and anorexia with no mortality

Herpesvirus Leporid Herpesvirus 1 (Herpes Sylvilagus)

Herpes Simplex

Herpes-like viral infections RNA Viral Infections Calicivirus

Lymphoproliferative disease, lymphoid hyperplasia to lymphosarcoma

Epstein Barr virus analog

Non-suppurative meningoencephalitis with Experimental model for necrosis of neurons and herpes simplex prominent intrnuclear encephalitis inclusion bodies in neurons and astroglial cells necrosis in spleen, dermis, Hemorrhage, lungs, adrenald, Intranculear hydropericardium eosinophilic to amphophilic inclusions

transmissibel to European Rabbits (Orytolagus) and cottontails

South american type and Californian type intracytoplasmic inclusions in the that causes lethal affected epidermis only (not disease of mesenchyme) and conjunctiva; myxomatosis in Insect transmitted European rabbit (Orytolagus) ??Inclusions in the epithelium and mesenchyme??

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 Not a natural pathogen thymus, and lymph nodes, proliferative changes in glomerular tufts and uveitis

myocardial degeneration and necrosis

Rotavirus Rotaviral enteritis

similar lesions to coronavirus

Miscellaneous Sendai virus Rabies Bacterial Infections Respiratory Bacterial Infections

Upper respiratory tract following intestinal innoculation racoon variant rabies

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

Pasteurella multocida Serotype A and sometimes D

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

Bordatella bronchiseptica

suppurative bronchopneumonia and interstitial pneumonia

peribronchial and perivascular cuffing

Asymptomatic usually

lymphoid hyperplasia

Cilia-Associated Respiratry Bacillus Enteritis Complex

5-12 week old rabbits Rotavirus Coronavirus

Clostridium

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

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

Enterohemorrhagic Strains (EHEC)

Lawsonia

damage to enterocytes, profuse diarrhea, dehydration and death

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 Disease) and colon and myocardium, transmural necrosis in cecum and colon rarely associated with Klossiella pneumoniae disease, normal hemorrhagic enterotyphlitis inhabitant S typhimurium and Salmonella enteritidis Vibrio

intracytoplasmic bacteria

DDX: listeriosis and staph (liver)

Mucoid enteropathy

Synonyms: mucoid enteritis, bloat, hypoamylasemia

teeth grinding, cecal impaction, gelatinous mucus in colon

Stomach distended with fluid and gas.

Other Bacteria Listeriosis

Staphylococcus aureus

acute fatal disease, Newborns may focal hepatitis, ascites, death typically is in advanced develop systemic enlarged mesenteric pregnancy listeriosis, stunting, lymph nodes meningoencephalitis skin, mammary gland, genital tract, conjunctiva, footpads, upper and lower respiratory tract. suckling kits, multifocal suppurative lesions in the Acute septicemic form skin, lung, kidney, spleen, heart, liver Chronic suppurative lesions

Mastitis Respiratory Pododermatitis

Treponema paraluiscuniculi

Venereal spirotrichosis

swollen, red

ddx: Pasteurella, Listeria, and Tyzzers

ddx: Staph, Pasteurella, Streptococci

mucopurulent rhinitis and localized bronchopneumonia and abscesses sore hocks

vulva, prepuce, anal, muzzle, periorbital

edema, erythema, papules at mucocutaneous junctions

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

Mycotic Infections

straw colored fluid in the abdominal cavity. Miliary pale foci of suppurative hepatitis in liver. Placenta is thickened with friable surface

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

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

Dermatophytosis

Aspergillus

Pneumocystis carinii

Trichophyton metagrophytes

head and ears, paws, alopecia, crusting raised

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

pulmonary granulomas, well circumscribed, central coagulation necrosis Pulmonary edema, congestion of alveolar vessels, thickening and hypercellularity of septaw, mononuclear and PMNS

Parasitic Diseases

Coccidia

Intestinal

Heaptic

Encephalitozoon cuniculi

Obligate intracellular microsporidian parasite

Kidney: Focal irregular depressed areasGranulomatous nephritis Phacoclastic uveitis and cataracts

Eimeria intestinalis, Eimeria flavescens,

Eimeria steidae

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

Lung, liver, CNS also granulomatous lesipons

Ingested sporulated oocysts release sporozoites invade enterocytes and multiply (Shizonts) --> Gametogeny --> Oocysts

Sexual life cycle causes destruction of enterocytes and cells of the lamina propria. Cecotrophy does not infect because the oocyst require sporulation at room temp overnight

Sporozoites invade Histo: Periportal duodenal mucosa and fibrosis, dilation of spread systemically, bile 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--> epithelial cells oocysts released in to overlying collagenous bile 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

Cryptosporidium cuniculus Toxoplasma gondii Pinworm

Bylisascaris procyonis

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

cerebrospinal disease

torticoolis, ataxia, circling, opisthotonus

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

Nematodirus Trichostrongylus Taenia pisiformis (Cysticercus)

Psoroptes cuniclui Cheyletiella parasitovorax

Sarcoptes scabei

Multiple or single white noduels, necrotic centers with inflammation and fibrosis Proliferative and Obligate non burrowing hyperkeratotic otitis externa mites with euxdation mostly oily Dorsal trunk, scapula, ventral abdomen (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

non-pruritic scaling dermatitis with patchy coalescing alopecia

histo- Hyperkeratosis, interface dermatitis and folliculitis, reduced sebaceous glands and perifollicular fibrosis

One case was associated with a thymoma

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

Ulcerative Pododermatitis

circumscribed ulcerative Poor sanitation, trauma, and staphylococcus is most area covered by wire cages are implicated frequently implicated granulation tissues

Prolapse of the deep gland of the third eyelid

may be due to laxity in the supporting connective tissues

Vertebral fracture

can lead to incontinence

Tracheal injury following intubation

Erosive to ulcerative tracheitis

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

Cardiomyopathy associated with Ketamine/Xylazine/ detomidine

Multifocal myocardial degeneration with interstitial fibrosis

Site is usually lumbosacral L7 with hemorrhage around the psoas muscles

Insufficient dietary predisposing factors include roughage, poor gastric excessive grooming and hair motility, and sedentary chewing due to boredom lifestyle are more important

usually asymptomatic, frequently in animals used for antibody production and cholesterol studies Attributed to ischemia secondary to vasoconstriction with reduced coronary blood flow

Metastatic mineralization of the aorta Renal Amyloidosis sparing of the gloeruli Nutritional muscular neonatal mortality and Vitamin E deficiency dystrophy infertility Calcium and Vitamin D Osteomalacia, deficiency overgrowth Medial degeneration In long bones there is and mineralization of depostion of basophilic Hypervitaminosis D major arteries, material (osteoblasts) on the glomerular tufts, tubular periosteal and endosteal BM surfaces Poor ceonception, congenital Microencephaly, Hypo or Hyper Vitaminosis A abnormalities, fetal hydrocephalus, cleft palate reabsorbtions Chronic Renal Failure

pale mineralized streaks in muscle

Pregnancy toxemia

Lead Toxicosis

Mobilization of fat Obesity, hereditary, imparied deposits leads to blood flow, pituitary metabolic acidosis and dysfunction all predisposing ketosis with fatty liver factores Myocardial degeneration, Anemia, tremors, and hepatic necrosis, renal posterior ataxia tubular degeneration, hemoglobin casts

Hereditary Disorders

Congenital Glaucoma (Buphthalmia)

Malocclusion

Endometrial Venous Aneurysms

New Zealand White Rabbits

Enlargement of 1 or both eyes with corneal opacity

Autosomal recessive, Absence or underdevelopment of the outflow channels with incomplete cleavage of the iridocorneal angles

overgrowth of premolar and Autosomal recessive, molar teeth also occur (seen the mandible is long in in animals with diet deficient relation to the maxilla in calcium and vitamin D) Persistent urogenital Blood filled endometrial bleeding, clotted blood varices consisting of dilated in uterus thin walled veins

Neoplasms Most common Nodular frequently spontaneous neoplasm Cauliflower like surface Serosal implantation and Uterine Adenocarcinoma multicentric enlargements of in Oryctolagus and central ulcerations metastasis to the lung and liver one or both uterine horns cuniculus Kidney and gastric In cottontail has been Liver is enlarged, pale, and Leukemia only mucosa most common Lymphosarcoma associated with Herpesvirus swollen, spleen is large and lymph occasionally occurs sites, confined to renal sylvilagus nodes large cortex Stomach wall is thick with irregular plaques and mucosal ulceration Aside from thymic involvement there may be variable lymphocytic 1 case of hypercalceima and Thymoma infiltrates in the other exfoliative dermatitis organs like, lymph nodes, liver, heart, and lungs Swelling of 1 or more mammary glands with Prolactin-producing Pituitary Dilated cystic ducts lined by enlargement and Adenomass with Associated flattened cuboidal epithelium discoloration of the Mammary Dysplasia with papillary projections teats, thinning of haircoat

Common Mice Strains Common Diseases C57BL/6 (B6)

Back ground strain, longevity Melanism- coat color, heart valves, splenic capsule , meninges

Hydrocephalus 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