Rodent Medicine Flashcards
1
Q
Elodontomas (squirrels)
A
- Prairie dogs and Richardson’s ground squirrels
- Uncommon in hystricomorphs and rare in other rodents
- Progressive accumulation of odontogenic tissue at incisor apices
- Associated with incisor dystrophy
- Cause of respiratory compromise and death in some cases
- Extraction difficult, consider sinus trephination to relieve respiratory
symptoms
2
Q
Hepatic carcinomas (squirrels)
A
- Over-represented in ground squirrels and prairie dog
- Also identified in California ground squirrels, woodchucks, arctic ground squirrels
- Associated with a species-specific hepadnavirus
- Immunohistochemistry not commercially available - link to other soft tissue tumours unknown
3
Q
Other neoplasms reported in squirrels
A
- Hepatic adenoma
- Giant cell sarcoma
- Lipoma
- Myelolipoma
- Squamous cell carcinoma
- Surgical excision where possible
4
Q
Fluid therapy (hystricomorpha)
A
- Intravenous catheterisation difficult - cephalic vein = primary site; lateral saphenous in chinchillas
- Intraosseous catherisation often more appropriate in critical patients - femur (via trochanteric fossa); tibia (via tibial crest)
- Subcutaneous - non-critical patient rehydration; avoid interscapular fat pad in guinea pigs
- Oral fluids - route of choice for slow rehydration where GIT is functional (nasogastric tubes tolerated poorly)
5
Q
FT - technique (hystricomorpha)
A
- Sterile technique under anaesthesia
- Use spinal needle/hypodermic needle
- Ongoing analgesia necessary
- Prophylactic antibiotic cover
6
Q
Blood sampling sites (hystricomorpha)
A
- Jugular
- Cephalic
- Femoral vein
- Cranial vena cava
7
Q
Jugular blood sample (hystricomorpha)
A
- Short, thick neck with much SC fat
- Difficult to visualise and restrain for sampling
8
Q
Cephalic blood sample (hystricomorpha)
A
- Small volumes in guinea pigs and chinchillas
9
Q
Femoral vein blood sample (hystricomorpha)
A
- Distal femoral vein - small but identifiable visually
- Typical sample size of 0.2 mL)
- Blind technique proximally for larger volumes - palp femoral artery pulse
and insert parallel and superficial to this
10
Q
Cranial vena cava blood sample (hystricomorpha)
A
- Anaesthesia necessary
- Large volumes possible
- Useful in small species, debilitated animals
11
Q
Dental disease, difference in anatomy - guinea pig
A
- Similar pathologies to rabbit dental disease +
some guinea pig specific - 1 incisor, 1 premolar and 3 molars in each quadrant
- Occlusal plane slanted at 30 degrees
12
Q
Guinea pig dental disease
A
- Lower cheek teeth curve towards tongue, overgrowth affects chewing + swallowing -> dec in tongue movement
- Can be complicated by hypovitaminosis C
- Impossible to evaluate dentition fully in the conscious animal
- CS: reduced appetite/dysphagia; reduced grooming; weight loss; change in faeces; drooling; ocular discharge uncommon
- GA and retraction of soft tissues necessary for
complete oral exam - short fast period useful (2 - 3 h prior, then syringe feed after)
13
Q
Objective dental evaluation - radio (GP)
A
- Maxillary apices - rostral end of the nasal bone to dorsal notch of the tympanic bulla (about three quarters of its height)
- Occlusal plane - rostral surface of the mandibular incisor (normal length) to the notch of the tympanic bulla
14
Q
Dental disease management (GP)
A
- Radiographic and coronal assessment of changes
- Reshaping and shortening of crowns - high speed diamond burr
- Avoid clipping teeth to limit iatrogenic trauma
- Gingival resection where necessary w/ profound overgrowth of single tooth spur (not beneficial if multiple)
- Consider pulpectomy - only applicable for mandibular pathology, limited applications
- Analgesia
- Supportive feeding
- Prophylactic Vitamin C
15
Q
Primary incisor pathology (GP)
A
- Rare - due to rostrocaudal movements of skull
- 2y malocclusion results from cheek tooth elongation
16
Q
Resp disease (GP)
A
- 2y to immunosuppression (to bacteria or irritants in environment e.g. NH3) - concurrent disease, poor husbandry, nutritional deficiency
- Susceptible to bacterial infections when kept w/ other species - Bordetella + Pasteurella from rabbits
- Adenovirus related pneumonia in stressed/older GPs - reduced func lung space
17
Q
Cystic ovaries (GP)
A
- Most common endocrine disease in GPs ( > 75% adult females at necropsy, aetiology unknown)
- Single/multiple cysts affecting both ovaries
- Abdominal distension
- Non-specific signs of discomfort
- Functional cysts cause non pruritic flank alopecia
- Manage surgically
18
Q
Dermatophytosis (GP)
A
- Trichophyton mentagrophytes (does not fluoresce with Woods lamp)
- 6-14% GPs asymptomatic
carriers - CS: alopecia, non-pruritic scaling, usually face and legs
affected (erythema) - Dx - microscopy/dermatophyte culture
19
Q
Dermatophytosis Tx (GP)
A
- Treat all in-contact animals
- Topical enilconazole or miconazole
- Oral itraconazole (risk of hepatotoxicity)/terbinafine (lower down cascade)
- Oral griseofulvin (25 mg/kg sid for 3 - 5 w)
- Sand bath treatment in chinchillas
- Difficult to eliminate in large groups
20
Q
Trixacarus cavidae
A
- Sarcoptic mite - present in low numbers , more common
- Clinical disease may be precipitated by stress/immunosuppression/hypovitaminosis C
- Intense pruritus can lead to self trauma and “seizures” (not true seizures. intense pruritus = uncontrolled spasms)
- Abortion/foetal resorption seen in pregnant
sows - Dx deep skin scrapes
21
Q
Trixacarys cavidae Tx (GP)
A
- 0.4mg/kg Ivermectin s/c weekly for 3 weeks
- Treat all affected animals in the group + clean housing well
22
Q
Pododermatitis (GP)
A
- 2y to poor conditions: abrasive flooring, obesity, irritants (urine, faeces, chemicals), hypovitaminosis C - dec collagen, inactivity, abnormal weight loading
- CS - erythema, swelling and ulceration of plantar and palmar surfaces
- If left, osteomyelitis and tenosynovitis can develop
- Avascular regions complicate recovery
23
Q
Pododermatitis Tx
A
- Address husbandry
- Topical and systemic
antibiosis: Flamazine speeds recovery; Preparation H - Analgesia
- Avoid debridement where
possible as contaminated - Prone to relapse
24
Q
Ocular disease (GP)
A
- Subclinical lens abnormalities - commonly congenital, often in pigment diluted strains
- Cataracts
- Fatty/pea eye - aetiology poorly defined, tend to affect overweight GPs on inappropriate diets
- Heterotopic bone formation - Keratitis - often related to trichiasis, especially in Rex
- Microphthalmos
25
Q
Cystitis (GP)
A
- Rule out urolithiasis (often consequence of cystitis)
- Causative factors - stress, dehydration, reduced mobility (physical/psychological causes), high calcium/oxalate diet?, bacterial involvement
- Manage causes as well as consequence
26
Q
Cystitis Tx (GP)
A
- Remove stone if present
- Analgesia - Meloxicam 0.6-0.8mg/kg bid
- Nutraceutiacals
- PSGAGs (Polysulfated glycosaminoglycans) e.g. Cartrophen
- Increased fluid intake
27
Q
Cheilitis (GP)
A
- Inflam of lips
- Multifactorial disease - acidic/abrasive diet, hypovitaminosis C, 2y becondary bacterial/fungal infection, ?Pox viral involvement
28
Q
Cheilitis Tx (GP)
A
- Antimicrobials based on cytology - yeast/bacteri
- Dietary improvement
- Topical emollients
- F10 barrier cream anecdotally speeds recovery
29
Q
Dental disease (chinchilla)
A
- Similar dental anatomy to guinea pig
- Occlusal surfaces closer to horizontal
- Poor Px once roots distort mandibular or maxillary cortices
- Caries and coronal (cavities)
fragmentation - Gingival overgrowth
- Very sensitive mucosa
- Stoic animals - disease often advanced by presentation
- Dx - radiographs - staging + adequate correction
30
Q
Dystocia (chinchilla)
A
- Under-reported
- Relatively common presentation due to
foetal size - Similar approach to larger mammals
- Dx - US
32
Q
Dental disease (degu)
A
- Only situation where clipping cheek teeth may be necessary due to size
- Similar pathology to other cavimorph rodents
- Diet major factor - should be on hay-based diet, limiuted sugary foods
- Can tolerate mild-moderate changes better than other herbivorous rodents
35
Q
Blood sampling sites (myomorph)
A
- Lateral tail vein = rats/mice
- Femoral vein - visible in rats distally, blind technique under sedation/anaesthesia
- Cranial vena cava - site of choice in small rodents
36
Q
Dental disease (myomorph)
A
- Rarely a problem - molars are permanent, occasionally caries seen on poor diet
- Incisors may malocclude following trauma
- Regular burring under anaesthesia
- Sx removal (some mobility is normal in lower incisors, most marked in hamsters
- Hard to extract incisors w/o damaging mandible, risk of H+, incisors v low down
38
Q
Resp disease Dx approach (rat)
A
- Sneezing, nasal discharge, tachypnoea, “rattling”(cooing), head tilt (middle ear), reduced “thoracic spring”
- Porphyrin staining (red pigment around nose + eyes), anorexia, weight loss, hunched posture, ruffled coat, lethargy
- Screen for underlying disease
- Culture (nasal/tracheal swab or BAL)
- Mycoplasma pulmonis PCR, corynebacterium serology
- Radio - Px - severity of lungs
39
Q
Resp disease AB Tx (rat)
A
- Early Tx important
(In order of giving) - 1) . Tetracyclines E.g. doxycycline 2.5-5 mg/kg PO BID
- 2). Macrolides E.g. azithromycin 20 mg/kg PO SID
- 3). Fluoroquinolones E.g. enrofloxacin 10 mg/kg PO SID
43
Q
Ectoparasites (rat)
A
- Rarely 1y problem
- Accum in debilitated rodents
- Treat underlying cause
- Injectable ivermectin, 0.4 mg/kg SC
- Life cycle of rat mites usually ~21days
- Multiple treatments needed 2 - 3
- Tx of all in-contact animals
49
Q
Neoplasia (hamster)
A
- Skin neoplasia most common (epitheliotropic hymphoma)
- Soft tissue sarcomas
seen in older animals - Adenocarcinomata - oral/pouch glands; flank scent glands; gastric mucosa
50
Q
Epitheliotrophic lymphoma (mycosis fungoides)
A
- Older hamsters
- CS: Anorexia + weight loss, exfoliative dermatitis, scabbing + alopecia, concurrent demodecosis, variable pruritus
- Dx - biopsy/impression smears
- Tx - Chemotherapy generally unsuccessful, palliative corticosteroid therapy/Euthanasia
53
Q
Murine dermatitis complex (mice)
A
- Frustrating condition
- CS - severe pruritus and self-trauma
- Typically affecting the dorsal neck
-Multifactorial - parasitic, contact irritation, hypersensitivity, stereotypical self-trauma, frequently exacerbated by 2y infections - Dx - skin scrapes + hair plucks, cyto, microbiological culture
