Exotic Mammals: Guinea Pigs & Chinchillas Flashcards
What are male and female guinea pigs called? What are the young like?
- MALES = boars
- FEMALES = sows
pups are precocial - born with hair, open eyes, teeth, and can eat solid food
What is the average lifespan and adult weight of guinea pigs?
5-7 years
- MALE = 900-1200g
- FEMALE = 700-900g
When do guinea pigs reach sexual maturity? How long is gestation? What is the average litter size?
- MALE = 3 months
- FEMALES = 2 months
59-72 days (68 average)
2-4 average (1-13)
How are guinea pigs sexed?
MALE = grease gland at maturity, dot on top the Y on the urogenital opening
FEMALE = no dot on top of the Y of the urogenital opening
What is the palatial ostium?
fusion of the soft palate to the base of the tongue
- makes intubation difficult
What facilitates parturition in guinea pigs?
separation of the pubic tendon to allow >25mm separation
- does NOT separate if first breeding is at 6 months
How do guinea pigs give birth?
- do not nest
- rapid - only a few minutes between pups
- adults are placentophagic
- young are precocious and weaned at 3 weeks
What response do guinea pigs have when scared?
freezes in response to noises and stampedes in response to movement
Guinea pigs are neophobic. What does this mean?
any changes to environment, diet, or dishes can cause inappetance
How should guinea pigs be handled?
support trunk with one hand and hindquarters with the other one
What enclosure is best for guinea pigs?
- 101 in squared, 7” high —> 7 ft squared for first, add 2-4 for each additional
- solid sides for several inches from the bottom, then wire up the sides and top
- ventilation
- keep clean - copious amount of feces/urine is produced
What temperature range should be kept for guinea pigs? Why?
65-79 F —> prone to heat stroke
- supply sipper bottles
- avoid water bowels —> messy, food constantly in mouth
What bedding is discouraged for guinea pigs? What alternatives are used?
aromatic wood shavings and corn cob bedding
- Care Fresh
- Yesterday’s News
- Eco-straw
- wood pellets
- hay placed on top
What type of cage bottoms are avoided with guinea pigs? Why?
wire-bottomed
avoids buildup of moisture that predisposes to pododermatitis
What is a necessary addition to a guinea pigs enclosure?
hiding spot —> hide boxes, PVC pipes
- shy!
What may help with male aggression in guinea pigs? How can stress in hospital be decreased?
- raise together
- neuter
housing with a cage mate
What species should guinea pigs NOT interact with?
rabbits —> can be seriously affected by Bordetella bronchiseptica
- dogs and rabbits are common carriers
What is an important component to guinea pig diets? What 3 things is it needed for?
fiber —> hind gut fermenters!
- wearing teeth normally
- normal GI motility (indigestible fiber)
- maintain cecal flora (fermentable fiber)
What 2 things does low fiber in guinea pig diets cause?
- GI hypomotility —> enterotoxemia
- elongation of cheek teeth
What vitamin are guinea pigs commonly deficient in? Why? What is the best source?
vitamin C (require 10 mg/kg/day; breeding female requires 30 mg/kg/day)
lack L-gulonolactone oxidase required for conversion of glucose to ascorbic acid
fresh veggies —> supplements are labile and have <3 month shelf-life after food is milled
How long does it take for signs of hypovitaminosis C to appear?
Scurvy —> 2 weeks
- spontaneous bleeding
What vegetables are rich in vitamin C and are recommended for guinea pigs?
- broccoli
- asparagus
- brussels sprouts
- mustard greens
- collard greens
- okra
- spinach
- kale
- swiss chard
- bell peppers - red, yellow, orange
- dandelion greens
- parsley
What are 3 important parts of the guinea pig diet? What is typically avoided?
- free choice hay - high quality grass hay
- timothy-based guinea pig pellets 6g/100g/day (in addition to hay, not replacing)
- fresh vegetables high in vitamin C - 2 c/day
alfalfa —> high in protein and Ca, which leads to uroliths
What are some good treats for guinea pigs? What does excess cause?
grains, fruits
high in starch, low in fiber = dysbiosis, diarrhea
What is a crepuscular feeder? What exotic mammal practices this?
eat at twilight
Chinchillas (nocturnal!)
What has caused wild chinchillas to become close to extinction?
fur trade
- only recently domesticated
- limited gene pool descending from 11-13 chinchillas
What are 2 important aspects to chinchilla anatomy?
- long, delicate limbs and long tails are extremely fragile - fractures common
- palatal ostium - oropharynx communicates with the remainder of the pharynx through a hole in the soft palate
How are chinchillas used in research?
model for auditory disease —> large tympanic bullae
What is the average lifespan and adult weight of chinchillas?
10-15 years (20 yr max)
- MALE = 400-500g
- FEMALE = 450-700g
When do chinchillas reach sexual maturity? How long is gestation? Litter size?
7-9 months
105-118 days (111 average)
1-6 (2 average)
How do chinchillas give birth?
- pelvic symphysis does NOT separate
- no nests - provide a nest box or flat board in cage for birthing
- typically occurs in early morning with 1/2-1 hour between deliveries
- females are placentophagic
- young are precocious and weaned at 6-8 weeks
How do chinchillas behave?
- VERY active - need regular handling and socialization
- crepuscular and nocturnal
- quiet, barks, alarm calls
- males can projectile urinate when they feel threatened
How should chinchillas be handled? What is not recommended?
- support hind end and upper body + grasp base of tail
- cover exam table —> slippery, cold
- may jump!
- less is more —> can “fur slip” which will grow back in 6-8 weeks
holding by ears, back of neck, or by the base of the tail
What enclosure is necessary for chinchillas?
- large cage (225 in squared and 12” high due to high activity)
- room for climbing and jumping
- hide box
- dust bowl
What kind of flooring is best for chinchillas? What should be avoided?
solid +/- fine mesh
- wire —> pododermatitis
- wire wheels —> injury to fragile legs common
What bedding and water sources are required for chinchillas?
newspaper or recycled paper pellets (Yesterday’s news, Carefresh) —> change frequently
sipper bottles
Why are wood shavings not recommended for chinchillas or guinea pigs?
all wood shavings may release aromatic oils
cedar > pine > aspen
What is important for maintaining chinchillas’ coats? What does excess lead to?
dust baths several times per week —> blue cloud, blue sparkle, 9:1 silver sand to Fuller’s earth, diatomaceous earth, talc
conjunctivitis
What temperature must be maintained for chinchillas?
do NOT tolerate damp or hot environments over 72 F
- prefer 64-72 F —> risk of heat stroke
- very cold tolerant
What is the diet of chinchillas like?
herbivores, high fiber (recommend 20-35% minimum fiber from hay, grass, and vegetables)
- salt and mineral blocks unnecessary
What are 3 important aspects to a balanced diet for chinchillas?
- free choice hay - timothy or other high quality grass hay (NOT alfalfa)
- high quality, fresh pellets - long timothy pallets allow for ease of handling (1-2 tbsp/animal/day)
- 1-2 cups chopped greens/veggies - introduce gradually to avoid soft feces
What amount of treats are recommended for chinchillas?
no more than 1 tsp/day —> excess sugars can lead to dysbiosis, diarrhea, and obesity
What kind of dentition do guinea pigs and chinchillas have? How do they differ?
aradicular hypsodont - open roots continually grow —> I (1/1) C (0/0) P (1/1) M (3/3)
- GP = white incisors, 30 degree occlusion
- chinchillas = yellow incisors, flat occlusion
What is the normal HR, RR, and temperatures of guinea pigs and chinchillas?
GP = 240-310 bpm, 50-70 bpm (+ sniff), 99-103.1 F
CHINCHILLA = 100-150 bpm, 50-70 bpm, 98.6-100.4 F
What is normal gut sounds of guinea pigs and chinchillas like? What should be inspected in male chinchillas?
1-3/min —> abnormal is absent OR too high
inspect prepuce for fur rings
What temperature typically leads to heat stroke in guinea pigs and chinchillas? How should it be treated?
> 85 F
- cooling - use ice with caution (stressful), alcohol on feet and ears cool with evaporation, stop when mildly hyperthermic to avoid iatrogenic hypothermia
- fluid therapy
- steroids
- supportive care
(poor prognosis)
What are 2 predisposing factors to pododermatitis in guinea pigs and chinchillas? What can it lead to?
- obesity
- poor husbandry
- secondary invasion of Staph. aureus or other pathogens
- osteomyelitis
- tendon disruption
How is pododermatitis treated?
- improve husbandry - bedding, caging, cleaning schedule, avoid wire flooring
- weight loss
- proper wound cleaning, bandaging
- systemic antibiotics +/- surgical debridement
guarded prognosis with osteomyelitis, may require amputation
When are substrate hypersensitivities commonly seen? What occurs? How is it treated?
aromatic beddings, especially Cedar shavings
- respiratory disease
- pododermatitis
- secondary infection
remove shaving, supportive care if needed
Why are guinea pigs susceptible to hypovitaminosis C? What does this cause?
scurvy —> cannot convert glucose to ascorbic acid (lack L-gulonolactone)
vit C is required for collagen synthesis —> defective collagen, laminin, and elastin in blood vessels can cause spontaneous hemorrhage
What clinical signs are associated with scurvy in guinea pigs?
- joint and gingival hemorrhage
- tooth loosening, malocclusion
- teeth grinding
- rough hair coat
- lameness
- pathological fractures
- anorexia, diarrhea
- increased susceptibility of bacterial infection
How is scurvy diagnosed?
- supportive history and clinical signs
- radiographs show enlarged long bone epiphysis and osteochondral junctions
- confirmed with serum ascorbic acid levels (not common)
How is scurvy treated?
- parenteral vitamin C supplementation - 50 mg/kg/day until improved
- supportive care - fluids, analgesia, feeding (with proper vit C)
- antibiotics if indicated
(vitamin C is water-soluble and can be easily excrete in the urine, so uroliths are not as common with supplementation)
What are the most common causes of dental disease and malocclusions in guinea pigs and chinchillas?
- inappropriate diet
- genetics
- trauma
What are the most common signs of dental disease in guinea pigs and chinchillas?
- anorexia, decreased hay intake
- bruxism
- ptyalism
- diarrhea, GI stasis
- oral lesions
- oculonasal d/c
- facial swelling
- tongue entrapment in guinea pigs
How is dental disease in guinea pigs and chinchillas diagnosed?
- oral exam - limited if awake
- evaluate occlusion during skull palpation
- 5-view radiograph
- CT
- evaluate bullae and check for abscessation
Is this normal in guinea pigs?
yes —> continuously have ingesta in oral cavity, flush out for an accurate oral exam
Guinea pig oral cavity, radiographs:
roots go deep into skull!
Guinea pig oral cavity, obliques:
Guinea pig oral cavity, CT:
malocclusion, abscess in mandible
How are dental disease and malocclusions treated? What complicates prognosis?
long-term commitment + $$$ —> unlikely to cure
- occlusal adjustment to restore proper angle and remove sharp points +/- extractions
- tube feeding
- specially prepared food - moistened pellets, diced hay and greens, slurry
- fluids
- analgesia
abscessation - need surgical removal
What is the main cause of enterotoxemia in guinea pigs and chinchillas?
administration of antibiotics (normal flora is G+!) causes the overgrowth of Clostridium difficile or perfringens
- toxin leads to severe diarrhea and death
What antibiotics cause enterotoxemia?
- Penicillins, Cephalosporins
- Erythromycin, macrolides
- Lincosamides
- Tetracyclines
What history is associated with enterotoxemia?
recent use of antibiotics —> even “safe” antibiotics can affect the GI flora
What 3 treatments are used for enterotoxemia?
- fluids - IV > SQ, IO
- Metronidazole (caution in chinchillas) or Chloramphenicol
- analgesia
prognosis poor, better if recognized quickly
What are 5 safer antibiotics for use in guinea pigs and chinchillas?
- TMS
- Fluoroquinolones
- Metronidazole
- Chloramphenicol
- parenteral Penicillin (Bactrim)
What are the 3 most common etiologies of bacterial enteritis? In what animals is this most common?
- Salmonella typhimurium
- Salmonella enteritidis
- E. coli
(primarily from contamination of greens)
immunosuppressed
What are the most common signs of bacterial enteritis? How is it treated? Prevented?
weight loss, weakness, conjunctivitis, abortion
antibiotics, fluids, environmental decontamination
wash veggies before given to pets
What causes Tyzzer’s disease? How is it transmitted? What are the most common signs?
Clostridium piliforme
fecal-oral transmission in stressed or young animals
- unthriftiness
- diarrhea (enteritis)
- death
- HISTO = intestinal inflammation, focal hepatic necrosis
What are 5 additional bacterial causes of enteritis?
- Yersinia pseudotuberculosis - intestinal, LN abscesses
- E. coli - more common in weanlings, causing wasting, depression, and death
- P. aeruginosa
- Listeria monocytogenes
- C. perfringens
What causes parasitic diarrhea in guinea pigs? How is it transmitted? What signs are seen? How is it treated?
Cryptosporidium wrairi
fecal-oral transmission in immunosuppressed animals (immunocompetent should clear infection in 4 weeks) - potentially zoonotic
weight loss, diarrhea, death
no effective treatment
What causes parasitic diarrhea in chinchillas? What clinical signs are seen?
Giardia —> normally harbor in low numbers, increased numbers from poor husbandry and concurrent disease may be pathogenic
- appetite loss
- diarrhea
- poor coat
What is GI stasis? What small mammals do they most commonly occur in?
ileus
guinea pigs and chinchillas
What are 7 possible causes of GI stasis in guinea pigs and chinchillas? What is a possible progression?
- dental disease
- poor diet - low fiber, high carbs, excessive treats
- trichobezoars
- dehydration
- painful conditions
- metabolic disease
- rabbits unable to vomit —> ingesta either continues to move aborally or sits in place (painful = snowballs)
GDV (rare)
Wha are some treatments of GI stasis?
- sedation + decompression by orograstric/nasogastric tubes or trocharization (GDV may require surgery)
- treat underlying cause
- fluids (IV or IO)
- analgesia
- nutrition
poor prognosis, especially in hypovolemic or hypotensive
What causes constipation in chinchillas? What can this lead to?
inappropriate diet —> low fiber (no hay)
torsion or impaction (rapidly fatal)
What are the 2 most common causes of diarrhea in chinchillas?
- bacterial or parasitic infections
- inappropriate diet - sudden diet change, introduction to fresh foods, or high sugar (raisins, fruits, yogurt drops)
What is the main cause of rectal prolapse? How is it treated?
increased straining from constipation or diarrhea
- REDUCE - hyperosmotic solution to decrease swelling (dextrose, saline, sugar water)
- LUBRICATION
- DEBRIDEMENT, R&A
- purse-string suture
- antibiotics, analgesia, fluids
What are the 2 most common causes of respiratory disease in guinea pigs? In what guinea pigs is this most common?
- Strept. pneumonia
- Bordetella bronchiseptica - subclinically carried by dogs, primates, and RABBITS
young and stressed
What are signs of Bordetella bronchiseptica respiratory disease in guinea pigs? How is it diagnosed?
- purulent bronchopneumonia
- nasal d/c, dyspnea
- abortion
ELISA (Ab’s) + culture of exudates
What heart murmurs have been heard in chinchillas? What makes up a proper cardiac workup?
RARE
- VSD with tricuspid regurgitation
- dynamic RV outflow tract obstruction (with VMTH)
radiographs + echo +/- ECG
What reproductive disease is common in guinea pigs? What are the most common signs?
ovarian cysts
- abdominal distention
- decreased appetite
- lethargy
- bilaterally hair loss
- cystic endometrial hyperplasia
How are ovarian cysts diagnosed? Treated?
abdominal palpation + U/S
- ovariectomy
- drainage
- hormonal therapy
When is pregnancy toxemia most commonly seen? What causes it? What are some signs?
obese sows 2 weeks before to 1 week after parturition
negative energy balance
- anorexia
- severe lethargy
- dyspnea
- hypoglycemia
- ketonemia
- aciduria
- proteinuria
(grave prognosis)
What are 4 common causes of dystocia in guinea pigs? What can be used to treat it?
- obesity
- large fetuses
- uterine inertia
- parturition after 6 months, when the pubic symphysis fuses
relaxin —> releases fibrocartilage of the pubic symphysis
What are 2 common signs of dystocia in guinea pigs? How is it treated? Prevented?
- unproductive contractions
- vaginal d/c
C-section —> poor prognosis for sows and pups
have first litter before 6 months + OVH
What is paraphimosis? What are some signs? How is it treated?
fur ring - accumulation of fur under prepuce, common in chinchillas
stranguria, excessive grooming
sedation + lubrication + removal
What is the most common cause of metritis in chinchillas? When is it seen?
- retained fetus/placenta
- dirty environment
- difficult birth/dystocia —> damage to canal
postparturition
What are 5 clinical signs associated with metritis in chinchillas?
- purulent vaginal d/c
- anorexia, lethargy
- hyperthermia
- vulvar swelling
- agalactia
How is metritis in chinchillas treated?
- spay (ideal)
- flush uterus (future breeding desired)
- systemic antibiotics
- oxytocin - expel retained tissues
What are 4 other reproductive diseases seen in chinchillas?
- fetal resorption
- dystocia - over-sized fetus (sx required)
- ectopic pregnancy
- pulmonary trophoblastic emboli from placenta
Where are urinary calculi most commonly found in guinea pigs? What is the most common kind? What are they commonly related to?
kidneys, ureters, bladder, urethra
calcium carbonate
diet and hydration
What are the most common signs of urolithiasis? How is it diagnosed? Treated?
stranguria, hematuria, anorexia
- surgical removal —> stone analysis, culture
- diet change
What are the 2 most common causes of cervical lymphadenitis in guinea pigs?
- Strep zooepidemicus - Lancefield’s group C
- Strep moniliformis - zoonotic
What is the most common cause of cervical lymphadenitis? How is it treated?
Strep species are part of the normal oral flora —> oral trauma from coarse hay or dental disease cause bacterial invasion to nearby LNs
complete surgical excision —> cannot drain due to thick and caseous contents, allows for C&S
What is considered metabolic bones disease in guinea pigs? How does it appear? What are the 2 associated causes?
fibrous osteodystrophy
replacement of normal bone with fibrous tissue, giving it a moth-eaten appearance
diet and genetics
What are some clinical signs of fibrous osteodystrophy? How is it diagnosed? Treated?
lameness and pathological fractures due to poor bone quality
radiographs
- calcium supplementation
- diet change
What fractures are especially common in chinchillas? How are they treated?
long bone fractures —> hind limbs are long and delicate (esp tibia) with thin cortices
surgical repair or amputation (splints often inadequate)
What causes lymphocytic choriomeningitis in guinea pigs and chinchillas? What are the most common signs? How is it transmitted?
arenavirus infection, most common in breeding facilities or labs
meningitis and hindlimb paralysis
inhalation, ingestion, or direct contact with infected fluids —> zoonotic, clients may have headaches, vomiting, or fever
When is listeriosis most commonly seen in chinchillas? What causes it? What organs are most commonly affected?
ranches chinchillas with access to decaying vegetation
L. monocytogenes
liver —> disseminated in blood —> encephalitis, abortion, septicemia
What virus causes neurological disease in chinchillas? What signs are seen?
herpesvirus (human HV-1) —> zoonotic vs. reservoir
- begins with conjunctivitis
- seizures, ataxia
- recumbency
- respiratory distress
(poor prognosis)
What is the most common tumor in guinea pigs? What causes it? What are the most common signs?
leukemia —> type C retrovirus
- lymphadenomegaly
- hepatomegaly
- splenomegaly
How is leukemia in guinea pigs diagnosed?
CBC - leukemic —> differentiate from lymphosarcoma
(short disease process, poor prognosis)
What is metastatic mineralization in guinea pigs? What may be associated?
abnormal mineralization of visceral organs —> commonly incidental finding at necropsy, may cause organ dysfunction if severe (GI, renal, pulmonary)
vitamin/mineral deficiency or excess
