Laboratory Rodents Flashcards
Which organ has its medium sized arteries spared in polyarteritis nodosa? a. kidney b. mesentery c. pancreas d. lung
D. lung
Which strains of rats are predisposed to polyarteritis nodosa?
SD and spontaneous hypertension rats (SHRT); any rat with late stage CPN
What are two differentials for a mouse with a head tilt?
necrotizing arteritis and mycoplasma otitis –> ischemic necrosis of inner/middle ear
Which of the following is the key feature of Sialodacryoadenitis Virus? a. nonkeratinizing squamous metaplasia of ductal and acinar structures of the Harderian gland b. keratinizing squamous metaplasia of ductal and acinar structures of Harderian gland c. chromodacryorrhea d. ductal epithelial hyperplasia of the Harderian gland
a. nonkeratinizing squamous metaplasia of the ductal and acinar structures of the Harderian gland. Also coagulative to lytic necrosis of ductal epithelium, inspissated porphyrin and neutrophilic infiltrates
Which mouse strain is the most susceptible to Sendaui virus? a. C57BL/6J b. NOD c. BALB/cJ d. DBA
d. DBA
Necrotizing rhinotracheitis with intracytoplasmic inclusions, syncytia and type II pneumocyte hyperplasia are all common features of which disease in mice? a. Sendai virus b. Sialodacryoadenitis virus c. Ectromelia virus d. Respiratory strains of Mouse Hepatitis Virus
a. Sendai virus - infects resp. epithelium, middle ear epi, type II pneumocytes. Causes a perihilar to cranioventral to diffuse consolidation of lungs. Syncytia are also found in MHV but are in multiple organs, have a vasculocentric pattern and do not have the epitheliotropism of Sendai. Ectromelia is mouse pox and SADV affects the Harderian gland with potential secondary bacterial pneumonia.
All of the following are factors in developing Ringtail in mice except: a. high temperature b. low humidity c. inherited cornification disorders d. aged mice
d. old age. Young mice are predisposed to the disorder
Which bacteria is frequently co-infected with Filbacterium rodentium? a. Mycoplasma pulmonis b. Corynebacterium kutscheri c. Pseudomonas aeruginosa] d. Pasteurella multocida
a. Mycoplasma pulmonis
The mechanism of disease for filobacterium rodentium is? a. impaired mucociliary clearance b. necrosis of tracheal epithelial cells c. pulmonary abscess formation d. vascular degeneration
a. impaired mucociliary clearance. Necrosis of tracheal epithelial cells is in Sendai virus. C. kutscheri forms abscesses. Vascular degeneration is in Mouse Hepatitis Virus.
Tissue from a mouse. Which of the following is the most likely etiology?
A. C. kutscheri
B. M. pulmonis
C. F. rodentium
D. P. multocida
A. C. kutscheri is part of YAACSS and makes clouds of bacteria in its abscesses
The compound found in these are primarily:
a. Ym1 Chitinase
b. Major Basic Protein
c. Hemosiderin
A. Ym1 chitinase are the component of crytals in acidophilic macrophage pneumonia. They are rhomboid shaped and eosinophilic as opposed to the dark red hemoglobin crystals associated with hemorrhage. They are commonly found secondary to pulmonary tumors, pneumocystis, or chronic pneumonia and are most common in older B6, 129 and Swiss mice.
Tissue from a rabbit. Morph only.
Renal lymphoma. Kidney is primarily involved in rabbits.
Tissue from a guinea pigs. Name the disease and cause.
Lumps; similar to strangles. Caused by Streptococcus equi var. zooepidemicus. Morph would be bilateral suppurative submandibular lymphadenitis. Commensal in guinea pigs mouth and tropsim for LN’s of the head and neck. Can rupture and form abscesses in other organs.
Mouse. Name the condition.
Cutaneous horn. Likey caused by a murine papillomavirus.
Gerbil. Morph.
Adenocarcinoma of the ventral marking gland of the gerbil. Modified sebaceous glands. Hamsters have paired marking glands on either side of their lumbar spine, also they process testosterone. Gerbils have single marking gland on central abdomen, no other function but marking.
Tissue from a mouse. Cause and another organ affected. What is a resistant strain?
Murine poxvirus ( or ectromelia virus). Splenic and hepatic necrosis. C57/B6 is resistant.
Tissue from a rat. Name the disease, give the morph. Key histologic feature. What is another species that gets similar lesions? What strain of rat gets this spontaneously?
Polyarteritis nodosa. Multifocal to coalescing necrotizing and proliferative mesenteric arteritis. Fibrinoid necrosis of vessels. Beagles - beagle pain syndrome. SHR or spontaneous hypertensive rate.
Tissue from a ferret. Morph.
Caudal vertebral chordoma. Tail most common site, next most common is cervical vertebrae.
Tissue from a rat. Morph. Cause. Name another affected organ.
suppurative bronchopneumonia with bronchiectasis. Mycoplasma pulmonis = think cilia. Other affected organs are uterus, tympanic bullae (other ciliated areas). Not in joints in rats. Mycoplasma superantigens create lymphoid hyperplasia.
Hamster. Morph and cause.
Trichoepitheliomas from hamster polyomavirus-1.
Tissue from a guinea pig. Etiology?
Strep equi var. zooepidemicus. Causes cervical lymphadenitis. Name is “Lumps” disease.
What is the receptor for Mouse Hepatitis Virus?
CEACAM
Enterotropic MHV is also known as ________. What is a classic gross and histo lesion?
lethal intestinal virus of infant mice; lack of milk spot, villous bluting of intestine with SYNCYTIA OF VILLOUS TIPS
What is the most common clinical sign of murine norovirus (calicivirus) in mice?
nothing
Which gene defects result in clinically apparent murine norovirus disease?
STAT null mice and IFN-y null mice
What gene defects can lead to inability to clear murine norovirus?
STAT, IFN-y or RAG null mice. Either innate or adaptive immune deficit will lead to inability to clear it.
Epizootic diarrhea of infant mice (EDIM) is caused by _________? What is the histo lesion?
rotavirus; villous blunting without syncytia of MHV but has apical vacuolar degeneration of enterocytes.
Murine minute virus causes what clinical disease?
nothing!minute virus causes minute changes; cleared readily
Tissue from a mouse.Most likely etiology and potential sequelae?
Mouse chapparvovirus. Causes CKD over time.
Lactate dehydrogenase virus, an arterivirus, causes poliomyelitis in what strains of mice?
A. BALB/c
B. C3H
C. NSG
C. NSG mice exposed to LDV develop poliomyelitis in those mice that also have the Fv(1)n allele.
What paramyxovirus causes BALT hyperplasia, syncytia, intracytoplasmic and intranuclear inclusions, and squamous metaplasia in immunocompetent mice?
Sendai virus
Tissue from a mouse.What tissues are you most likely to see this in?
salivary gland, pancreas or kidney. Murine cytomegalovirus. Model for human congenital malformations.
What are 5 differentials for this lesion?
Tissue from a mouse. Etiology?
Ectromelia virus.This is splenic fibrosis from previous necrosis.
Rectal prolapse secondary to chronic typhlocolitis is a sequela of what etiologies in mice?
Helicobacter spp.; Citrobacter rodentium; Mouse Hepatitis Virus in susceptible strains; Mouse norovirus in STAT-/- or IFNy-/-
A cause of pronounced colonic hyperplasia in mice is?
Citrobacter rodentium, also causes “hose pipe”colon, thick and short.
Tissue from a mouse.2 viral causes and2 bacterial causes.
Ectromelia virus (pox), and MHV (corona). Hepicobacter hepaticus and C. piliforme (Tyzzer’s).
Tissue from a mouse. Etiology and 2 other affected organs.
This is Tyzzer’s disease caused by Clostridium piliforme. Hepatic necrosis with target lesion is classic.Also causes necrosis in heart and intestines (triad).
This commensal of the mouse respiratory tract commonly causes retroorbital abscesses in SCID mice.
Rodentibacter pneumotropica, heylii. Also causes subQ abscesses in any mouse, and pneumonia in immunocompromised mice. Also causes conjunctivitis in any mouse.
Tissue from a rat. Etiology?
Mycoplasma pulmonis. Typical cobblestone appearance of the lung.
Tissue from a rat. Etiology?
Filobacterium rodentium. CARbacillus.
Tissue from a mouse. Expected histologic finding.
Gram positive cocci with Splendore-Hoeppeli material, abundant neutrophils surrounded by epitheliod macrophages and then fibroblasts. Staph aureus.Botryomycosis.
Tissue from a mouse. Etiology? Significance for the facility?
Hymenolepis nana, rodent dwarf tapeworm with characteristic polar filaments and 3 hooks. This is zoonotic!
Tissue from a mouse. Etiology? What is the clinica significance.
A. Myocoptes musculinis
B. Radforida affinis
C. Radfordia ensifera
D. Myobia musculi
D. This is Myobia musculi, fur mite of mice. Has “bulging muscles” which differentiate it from Myocoptes musculinis which is chunky. Causes immune sensitization where M. musculinis does not. Radfordia affinis also has a bulging muscles look to it, but has two unequal claws on its second legs. R ensifera is in rats.
Tissue from a mouse. Etiology?
A. Ornithonyssys bacoti
B. Demodex gatoi
C. Psororgates simplex
D. Polyplax serrata
D. Polyplax serrata. This is the common louse of lab mice. A is the tropical rat mite, B. is not found in mice, C. is a follicular mite related to psorpotes. Polyplax serrata causes erythema, pruritis, anemia. Has been a vector for Mycoplasma coccoides (RBC parasite) and Francisella tularensis.
What is the significance of Oxyuris (Syphacia obvelata/muris and Aspiculuris tetraptera) infection in mice and rats in laboratory facilities?
Pinworms cause a Th2-skewing of immune system.
Tissue from a mouse. Special stain helpful in diagnosis?
A. Gram stain
B. Luna
C. GMS
D. Giemsa
C. GMS. This is the common appearance of Pneumocystis murina infection in an immunocompromised mouse. In immunocompetent mice, the disease is usually transitory. Best appreciated with a GMS or PAS stain, also IHC.
A gross differential diagnosis for Trichophyton mentagrophytes in mice is:
A. Staphylococcus aureus
B. Corynebacterium bovis
C. Polyplax serrata
D. Syphacia obvelata
B. Corynebacterium bovis is a good differential for ringworm in mice caused by Trichiphyton mentagrophytes. Causes local crusted, chalky lesions. Ring lesions not common. Is NOT autoflourescent.
Tissue from a mouse. Histologic features of hepatic necrosis and cytoplasmic invagination are common with infection of what bacteria? What is a potential sequelae if this mouse is an A strain mouse?
Helicobacter hepaticus or H. rodentium. Also causes proliferative typhlocolitis along with hepatic necrosis, cholangitis, bile duct hyperplasia. LESIONS ONLY FOUND IN IMMUNODEFICIENT MICE (A/JCr, SCID/NCr, BALB/cANCr, C3H/HeNCr, and SJL/NCr). In A strain mice, hepatocellular carcinomas can develop from infection.
What is unique about Sendai virus?
It can cause disease in immunocompetent mice.
Which strains of mice are predisposed to this lesion?
DBA, BALB/c, C3H
Fatty liver in micecan bea result of deficiency of what?
choline
This lesion can be associated with what causes?
cilia gene defects, theiler’s murine encephalomyelitis virus, polyoma virus, reovirus, LCMV (the zoonotic one!)
Clown mouse syndrome, pictured here, is associated with infection and recovery from what disease?
mouse hepatitis virus
This lesion is commonly secondary to what?
imperforate vagina - leads to muco/hydrometra.
This lesion is mediated by which complement protein?
C3 - membranoproliferative glomerulonephritis;commonly causes ascites/anasarca in mice
This condition in a mouse is called _________ and the material is _________.
hyaline glomerulonephropathy; NOT amyloid, PAS positive. basement membrane expansion. Comparable to CPN in rats.
This lesion in the middle or inner ear of a mouse is called ________is known for causing this clinical sign?
vestibular syndrome or polyarteritis; head tilt/circline/imbalance. Lesions in other tissues such as kidney.
What type of lymphoma is most common in mice?What is a DDx?
Follicular B cell lymphoma; mature lymphomas are more common in mice > 12 months of age. DDx is diffuse large B cell lymphoma.
Most likely etiology?
myoepithelioma. DDx would be mammary tumor, salivary gland tumor. Frequently myoepitheliomas are cystic and have both epithelial and mesenchymal differentiation.
Tissue from a mouse. Morph.
Harderian gland adenoma.
Name the disease and give 3 potential causes.
Mutlifocal ulcerative dermatitis of B6 mice. Genetic causes, ectoparasite sensitivity, secondary bacterial infection, immune mediated leukocytoclastic vasculitis.
Etiology? Histo lesions?
Ectromelia virua (pox virus). Histo lesion is balloon degeneration, ulceration, hyperplasia. eosinophilic intracytoplasmic inclusions. B6 mice are resistant! Intermediate susceptibility mouse strains required for cutaneous lesions to develop, otherwise die acutely.
2 etiologic differentials and one predisposing factor.
Corynebacterium bovis or Staphylococcus xylosus; immunodeficiency (not hairlessness). Also consider cutaneous lymphoma with secondary infection.
Name the disease and give two etiologies.
Botryomycosis. S. aureus or P. aeruginosa.
Morph and 3 causes.
Cutaneous papillomas. Murine papillomavirus. Genotype. Carcinogens.
Tissue from a rat. Morph?
Keratoacanthoma.
Morph and 2 causes.
Ascites/anasarca. Glomerulonephropathy, glomerular or intestinal amyloidosis. Atrial thrombosis,
Morph and 3 causes.
Focal lateral femoral hernia,; Estrogen treatment in males, androgen treatment in females, FVB substrain.
Tissue from a mouse. Morph and 3 causes.
Mammary lobuloalveolar hyperplasia. Causes: pregnancy, prolactinoma of pars distalis, FVB strain.
Morph and 3 Possible causes.
Mammary adenocarcinoma; carcinogens, mouse mammary tumor retrovirus, hormones, strain.
Tissue from a rat. This lesion is associated with:
A. Malignant transformation
B. Retrovirus induction
C. High tubule:stroma ratio
D. Fibroblast proliferation
D. This is a mammary fibroadenoma in rat, which are benign and not associated with retroviruses like they are in mice.
Tissue from a rat. Morph and histo feature. What strain of rat are these most common in?
Zymbal’s gland carcinoma. This is a modified sebaceous gland with ducts lined by keratinized squamous epithelium. Variable proportions of sebaceous and squamous cells. Differentials on histo are squamous papillomas of zymbal’s gland and SCC of adjacent tissue. Gross DDx is mammary tumor. F344 rats have the highest incidence but they occur in all rats, not common at all in mice.
Morph. 4 differential etiologies. Histo features.
Preputial gland abscess, bilateral. Caused by Rodentibacter pneumotropicus; Klebsiella oxytoca; Staphylococcus spp.; Streptococcus spp. Ducts lined by squamous epithelium, eosinophilic granular material in glands is normal, abundant neutrophils.
Name the condition. Give 3 causes. What is the pathogenesis?
Ringtail. Genetics (epidermal differentiation genes); low humidity; high temperature; hydration status.
Pathogenesis: Disordered cornification –> hyperkeratosis, abnormal desquamation –>persistent keratin ring –> strangulation –> gangrenous necrosis.
Tissue from an FVB mouse. Other location for this lesion and histo features.
This is a dermal coccygeal neural crest tumor. Pinna of the ear is the other common lesion. See image for histo (Schwannoma-looking).
Tissue from a mouse. Morph and cause.
Auricular chondritis. Cause is hypersesntivity reaction to copper and iron released from ear tags.