Rodent Diseases Flashcards
Causes of GI hypomotility/stasis in a guinea pig
- inadequate dietary fiber
- anything causing pain, anorexia/inability to eat
You should NOT give prokinetics if __________
animal has GI obstruction
Treatment for ileus in a GP
- fluids
- pain management (b/c humane and pain itself causes GI hypomotility)
- assisted feeding
- Vitamin C
- +/- prokinetics if not obstructed
- metaclopramide
- cisapride
Antibiotic-associated enterotoxemia in GP is usually a result of _________________
Clostridium difficile toxin
Etiologic agent of Tyzzer’s disease
Clostridium piliforme
Causes of bacterial enteritis in GP
- Salmonella
- Tyzzer’s (C. piliforme)
Endoparasites that GP get
- coccidia
- roundworms
Antibiotics to avoid in guinea pigs
- penicillin
- ampicillin
- lincomycin
- chlortetracycline
- clindamycin
- erythromycin
Hemorrhagic typhlocolitis in guinea pig
typical of toxin production; consistent with antibiotic associated enterotoxemia
Name a pathogen that might cause spots on the liver
Salmonella
Name antibiotics that are appropriate for use in GP
- TMS
- chloramphenicol
- enrofloxacin
- azithromycin
Symptoms of malocclusion
- weight loss
- anorexia (apparent or real)
- +/- ptyalism (slobbers)
- +/- facial dermatitis
What is an indicator of heat stress in rodents?
excess salivation
Malocclusion in GP is usually due to _________
molar issues
Bacterial enteritis in GP is usually caused by ______________
S. typhimurium
Abscesses are associated with malocclusion, especially in what species?
rabbits
What causes of diarrhea in a GP are associated with a concern for zoonosis?
Crypto, Salmonella
How is S. typhimurim transmitted?
fecal contamination of feed
Pathology associated with salmonellosis in GP
- often no gross lesions
- enlarged spleen & liver +/- yellow spots
- increased intestinal gas and fluid
- necrotic foci in spleen, liver, mesenteric LN
Bacterial pneumonia in guinea pigs is usually caused by what two agents?
- Bordetella bronchiseptica
- Streptococcus pneumoniae
*usually an underlying viral etiology
Clinical presentation of respiratory disease in a GP
- subclinical
- anorexia
- weight loss
- coughing, sneezing, nasal/ocular discharge
- dyspnea-acute death
- may cause otitis–>head tilt
Bordetella is especially bad in what species?
guinea pig
Mucopurulent rhinitis & otitis media in the GP are consistent with ______________
Bordetella bronchiseptica
Fibrinopurulent bronchopneumonia, pleuritis, pericarditis, peritonitis, and otitis in a GP are consistent with ______________
Streptococcus pneumoniae
What would be least appropriate for treatment of respiratory disease in a GP?
a. TMS
b. azithromycin
c. ampicillin
d. enrofloxacin
e. docycycline
c. ampicillin
Culture & sensitivity or serology is good for detecting what respiratory pathogen?
Bordetella bronchiseptica
Direct smears (tracea, bronchi) are best for detecting what pathogen?
Streptococcus pneumoniae
Top differentials for older GP with progressive loss of appetite, weight loss, +/- PU/PD, hematuria and dysuria or “sudden” death.
- chronic renal disease or failure (chronic interstitital nephritis)
- urolithiasis
- other things associated with anorexia/weight loss
Urinary calculi in GP are usually composed of what?
Calcium carbonate
Predisposing factors to urinary calcui in GP
- urethral plugs (old boars)
- older sows
- high calcium or Ca:P imbalance in diet
- bacterial infection
Ddx for urinary calculi in GP
cystitis (which is relatively common and minor)
Acidify urine in GP to treat calculi?
NO
Chronic renal amyloidosis in GP is associated with _____________
Staph pododermatitis
Diagnosis of chronic interstitial nephritis in GP
- +/- “lumpy kidneys”
- urinalysis
- serum biochemistry
What do you need to evaluate in a GP with dystocia?
pubic symphysis
Only use oxytocin in GP if symphysis separation is _______
>20-25mm
Breed GP before ______ months of age
7-8
Predisposing factors to dystocia in GP
- late breeding
- obesity
- large fetuses
Dermatologic ddx in GP
- dermatophytosis
- acariasis (fur mites) – usu. subclinical
- pediculosis (lice) – usu. subclinical
Non-dermatologic R/Os for alopecia in GP
- intensive breeding
- ovarian cysts
- barbering/self-barbering
Treatment for cervical lymphadenitis in GP
surgical excision of lymph nodes
Etiologic agent of cervical lymphadenitis in GP
Streptococcus zooepidemicus
R/Os for cervical lymphadenitis
abscess, neoplasia
Predisposing factors to cervical lymphadenitis
- malocclusion
- rough hay
- stress
Predisposing factors for pododermatitis
- obesity
- poor husbandry
- wire bottom caging, abrasive bedding
R/O for pododermatiitis
osteomyelitis
Prognosis for pododermatitis
guarded
“BIG THINGS” to remember for guinea pigs
- vitamin C
- GI tract-antibiotic sensitivity, ileus
- dental disease
- respiratory disease
- skin
- urolithiasis
Pathology of hypovitaminosis C
- hemorrhages into subperiosteum, SQ, skeletal muscle, intestine
- enlarged epiphyses-long bones
- enlarged CCJ
- pathological fractures
Malocclusion in rats is usually due to ________
incisor problem
Do molars grow continuously in rats?
no
Do molars grow continuously in GP?
yes
___________ causes murine respiratory mycoplasmosis
Mycoplasma pulmonis
Describe clinical symptoms of a rat with Mycoplasma pulmonis
- SRS (hunched, rough haircoat, weight loss)
- “snuffling/chattering”, nasal discharge, head tilt, squinting, chromodacryorrhea
- polypnea, dyspnea
What respiratory pathogen in rats has intrauterine transmission and can cause infertility?
Mycoplasma pulmonis
May cause an acute pneumonia in rats
Streptococcus pneumoniae
Pathology associated with murine respiratory mycoplasmosis
- otitis media
- atelectasis, bronchiectasis, consolidation of lungs, bronchial abscess
Tx for M. pulmonis
- enrofloxacin, doxycycline
- azithromycin
- in vitro sensitivity to tetracycline, tylosin
Other respiratory pathogens (aka often coinfection with M. pulnonis) in rats include:
- Sendai virus
- cilia-associated respiratory bacillus (CAR)
- Corynebacterium kutscheri
Treatment for rat chronic respiratory disease
- doxycycline +/or enrofloxacin
- doxy also has anti-inflammatory properties
- azithromycin
Prevention of chronic progressive nephrosis
caloric restriction?
S. aureus dermatitis is usually secondary to ____________ in pet rats
ectoparasites
Do rats fight commonly?
no
Drugs effective against pinworms
- ivermectin
- fenbendazole-in feed convenient
- selamectin
A local pet store contacts you about a new shipment of mice. There are several adult female pruritic mice with variable alopecia, scabbing, and crusting around ears and neck. What is the most likely underlying cause?
fur mites
(pet mice-top ddx ectoparasites)
What is the role of N-acetylcysteine and glutathione in “mouse ulcerative dermaitis”?
antioxidants
Cause of proliferative ileitis
Lawsonia intracellularis
Other ddx for “wet tail” in hamsters
- clostridial enterotoxemia (similar to GP; Antibiotic-associated)
- colibacillosis
- salmonelosis
- Tyzzer’s
Possible sequellae associated with proliferative ileitis
- chronic, inapparent infection
- rectal prolapse
- intussussception
Stain for amyloid?
congo red
Important behavioral issues associated with hamsters
- cannabalism of young
- fighting
Lethargy, rough haircoat, +/- watery diarrhea, and death in a gerbil is most likely due to ____________
Tyzzer’s
Clostridium piliforme
Silver stain is used for _______________
Clostridium piliforme
Transmission of Clostridium piliforme
fecal-oral
How do you treat gerbils with seizures?
no treatment-no need and will likely die from treatment with anti-seizure drugs
“tail slip” occurs in what species?
gerbils
What is tail slip?
loss of hair/skin on tail caused by picking the gerbil up by its tail
“Sore nose” in gerbils is caused by ____________
high environmental humidity (>50%)
Etiology of MHV
a coronavirus
MHV is seen in what age mice?
mostly pre-weanlings
Pathology of MHV
- absence of milk in stomach of sucklings
- flaccid, distended gut
- +/- pale liver with pale spots (multifocal necrosis)
Clinical signs and PE findings of what else look similar to GI stasis in guinea pigs? how do you distinguish?
gastric/cecal dilatation/torsion look similar. Distinguish with abdominal imaging
Clinical signs of Tyzzer’s dz in GP
- lethargy/anorexia
- diarrhea
- unthrifty appearance
- acute death
C. piliforme culture considerations
does not grow on routine media
Definitive dx of C. piliforme?
histopath ID of organisms on liver or intestinal sections
Y. pseudotuberculosis pathology
abscesses of intestine, liver, regional LN
Fecal impactions in guinea pigs-most common in what group?
older guinea pigs; especially boars
Best ways to get diagnostic C/S samples for respiratory dz in guinea pigs
tracheal secretions, bronchoalveolar lavage, or fresh necropsy specimen bronchopulmonary region
Rad findings in GP with respiratory disease
opacity within tympanic bullae or lungs
Species that can be asymptomatic carriers of B. bronchiseptica
Rabbits, dogs, nonhuman primates
Other lesions often identified with renal lesions in GP
Cardiac lesions (epicarditis, myocardidits, fibrosis, pericarditis, ventricular dilation)
Treatment of pregnancy ketosis in GP
IV or IO isotonic fluids with dextrose; oral glucose; NUTRITION(critical care formulas)
Success of treating pregnancy toxemia/ketosis?
- generally not successful
Prevention of preg. toxemia in GP
- avoid stress/obesity/diet changes or environment changes in late pregnacy
- increase CHO during last 2 wks gestation and early postpartum
- exercise encouragement before breeding to minimize obesity
- avoid postpartum breedings
Mammary tumors in GP
- 50% malignant but metastasis not common
- boars as well as sows
- usually fibroadenomas
Clinical signs of dematophytosis in GP
scaly, patchy lesions on feet, face, dorsum
- circular areas of alopecia; pruritic
Dx of dermatophytosis
fungal culture of hair pluck or skin scraping; req. dermatophyte test medium
Are there products labeled for GP for ectoparasite treatment?
no
How do GP get cervical lymphadenitis?
normal flora of oropharyngeal/nasal region–>mucosal abrasion–>invasion of deeper tissues & cervical LN
Dx of cervical lymphadenitis in GP
- impression smear & gram stain (G+ cocci chains)
- culture exudate (B-hemolytic)
Most common tumors of GP
Trichofolliculomas; males; often incorporate the scent glands; excision usually curative; benign
Treatment of a fibropapilloma of ear canal in GP
nothing-usually resolve spontaneously
Most common malignancy in a GP
lymphoma
What disease agents are associated with otitis media?
- B. bronchiseptica
- S. zooepidemicus
- S. pneumoniae
- sometimes M. pulmonis
Symptoms of lymphocytic choriomeningitis virus in GP
- meningitis
- hind limb paralysis
Average mouse lifespan
1.5-2.5 years
Average rat lifespan
2-3 years
Average hamster lifespan
1.5-2 years
Average gerbil lifespan
2-4 years
Mammary tumors in rats
- almost always benign fibroadenoma
- generally well-tolerated until large and ulcerated/interfering with locomotion
- Sx, consider OVH
- recurrence common
S. moniliformis & Spirillum minor cause ________in humans
Rat-bite fever
Transmission of SDAV
direct contact or aerosol
CS of SDAV in rats
- inflammation/edema of cervical salivary glands
- rhinitis, sneezing
- secondary ocular signs d/t lacrimal dysfuntion
Three major respiratory pathogens in rats
- Mycoplasma pulmonis
- S. pneumoniae
- Corynebacterium kutscheri
Chronic progressive nephrosis (rats) occurs earlier and is worse in what sex?
males
MHV transmission
- fecal-oral
- aerosolization
- fomites
Top ddx for diarrhea in adult hamster?
C. difficile; antibiotic administration-associated
C. difficile may cause hemorrhagic ileocolitis in _______
hamsters
Weight loss in older hamsters usually associated with ________________
hepatic or renal amyloidosis
Is renal amyloidosis more common in male or female hamster?
Female
_________have ventral abdominal marking glands
gerbils
Cause of gerbil seizures
- inherited deficiency of cerebral glutamine synthase
What rodents are susceptible to streptomycin toxicity?
Gerbils
________ are susceptible to streptomycin and procaine toxicity
mice
Pasteurella pneumotropica causes ______ in mice
conjunctivits
What are Kurloff bodies?
- mononuclear cells approximately the size of a large lymphocyte. They have a large, round, purple nucleus that is often eccentrically located and blue cytoplasm. The distinguishing characteristic of this cell is a very large, slightly granular, magenta, cytoplasmic inclusion body
- normal in 2-4% of guinea pig lymphocytes