Midterm Flashcards
Taxonomy of Hamsters
- Order: Rodentia
- Suborder: Myomorpha
- Family: Cricetidae
- Sub-Family: Cricetinae
- Genera: Mesocricetus, Cricetus, Cricetulus, Phodopus, Tscherskia
Taxonomy of Mice
- Order: Rodentia
- Suborder: Myomorpha
- Family: Muridae
- Genera: Rattus
- common Spp.: Rattus norvegicus and Rattus rattus
Taxonomy of Rats
- Order: Rodentia
- Suborder: Myomorpha
- Family: Muridae
- Genera: Mus
- species: musculus
Taxonomy of Gerbils
- Order: Rodentia
- Suborder: myomorpha
- Family: Cricetidae
- Sub-Family: Gerbillnae
- Genera: Meriones
species: Meriones unguiculatus
Taxonomy of Rabbits
- Order: Lagomorpha
- Family: Leporidae
- Genera:
- species: Oryctolagus cuniculis, Lepus spp., Sylviligus spp.
Taxonomy of Guinea Pigs
- Order: Rodentia
- Suborder: Hystricomorpha
- Family: Caviidae
- Genera: Cavia
- species: Cavia porcellus
Taxonomy of Chinchillas
- Order: Rodentia
- Suborder: Hystricomorpha
- Family: Chinchillidae
- Genera: Chinchilla
- Species: C. lanigera and C. Chinchilla
what are some common hamster species(7)
- Syrian (golden) hamster–> most common, many color varieties
- Angora (“teddy-bear”) –> long haired variety
- Siberian (Russian) hamster
- European (“black belly”) hamster
- Armenian (grey) hamster
- Chinese (“Dwarf”) hamster
- Long-tailed hamster
Where did hamsters originate? How did they get to Israel?
1930: one female w/ offspring taken from Syria to Israel
Where do almost all Syrian and laboratory hamsters derive?
the first female and her offspring that were taken from Syria to Israel
In what years were Syrian hamsters first taken to Britain? The U.S.?
- 1931
- 1938
In what year were several inbred strains of Syrian hamsters developed for research?
1960s
What are some lab uses of Syrian hamsters in research?
- Dental research
- cancer research
- immunology (xenotransplants)
- infectious disease
- hypothermia
- parasitic diseases
- teratology
- reproduction
- vascular physiology
- genetics )dilated cardiomyopathy)
Bio data of Hamsters
Adult size: 5-7 inches long
Adult BW: 85-150g
Lifespan: 2-3 yrs
Urine Volume: 5.4-8.4 ml/day
bio data of Rats
Adult BW: 250*500g
Lifespan: 2-3 yrs
Urine Volume: 3.3ml/100g body wt/day
bio data of mice
Adult BW: 20-40g
Lifespan: 1.5-3 yrs (2 avg)
Urine Volume: 0.5-1.0 ml/day
Bio data of gerbils
Adult BW: 70-110g (males); 55-90g (females)
Lifespan: 3-4 yrs
Urine Volume: 3-4ml/day (very small output)
bio data of guinea pigs
Adult size:
Adult BW:
Lifespan:
Urine Volume:
bio data of chinchillas
Adult size:
Adult BW:
Lifespan:
Urine Volume:
Which species have very small urine output?
- Gerbils
Unique characteristics of chinchillas
- soft, dense fur over body, little to no hair on ears
- large cecum, coprophagic
Incisors and molars are open-rooted, will continue to grow throughout life - incisors should be YELLOW/ORANGE colored
Describe the paws of a chinchilla
- four digits on each paw
- front paws can grasp food
- each digit has a flat nail, like humans
- first digit on back foot has small bump on top w/ course hairs sticking out
Sexing Chinchillas
Can use anogenital distance, but its hard to do bc you typically don’t have anything to compare them to
- can use digital pressure to extrude penis from sheath
- females have an elongated urinary papilla with a slit, and usually a noticeable vagina even when not in estrus
T/F chinchillas have a large output of urine
False, its small bc they don’t drink a lot of water
Is it normal for chinchilla urine to be orange/red in color
Yes
T/F chinchillas are primarily nocturnal or crepscular
True
Can chinchillas be easily aroused during the day?
Yes
Why should chinchillas have a vertical cage?
Because they’re jumpers and climbers
Are chinchillas generally aggressive?
No, they’re fairly social
If there are multiple chinchillas how can they be housed?
In single-sex pairs or groups with proper introduction
T/F Female chinchillas can stand on hind legs and spray with urine
True
Why does mounting not matter in determining chinchilla sexing
Because both male and females will mount each other to establish dominance
T/F chinchillas are quiet creatures
No they’re loud af
How should you handle Chinchillas?
- grasp by base of tail, support back end either with other hand or against chest
- can also wrap in a “burrito”
- be careful holding, they have a delicate bone structure
- fur slip potential —> handle fur gently
Diet of Chinchillas
- hindgut fermenters, strictly herbivorous
- unknown nutritional requirements
- high fiber, low energy pellet diet (either chinchilla specific or comparable rabbit pellets)
- use Timothy or orchard grass hay
- don’t need supplements
What are your general feeding directions for Chinchillas?
Water bottle or bowl?
Feed, water, and hay ad libitum
Water bottle, they play with bowls
Describe features of chinchilla housing
- around room temp, don’t go above 75F
- keep low humidity (<40%), out of direct sunlight, well-ventilated
- Wire mesh cage typical, solid bottom cages best
- do NOT use glass aquariums (urine can scald the glass)
- use absorbable bedding (not cedar)—> aspen, kiln-dried pine bedding
- wooden shelves, provide with many chewing opportunities (toys, hiding boxes)
- give them a dust bath at least once per week, but don’t leave in there or they’ll use it as a litter box
- give them a large solid running wheel (no bars)
Estrous cycle of Chinchillas
- seasonally polyestrous
Cycle lasts 38-40 days
Gestation period of chinchillas
111 days
When do chinchillas give birth?
In the morning
Chinchilla young are ___, which means what?
- precocial
- fully furred, eyes and ears open, full set of teeth —> hits can be aggressive toward each other if not enough milk
When do chinchilla kits start eating solid food?
When are they weaned?
Around 1-3 weeks
At 6-8 weeks
What is so special about the male chinchilla’s inguinal canal?
It is open, and so when they are aroused, the testes bulge slightly on either side of the penis and the caudal epididymides protrude into postanal (scrotal) sacs
Successful breeding of chinchillas may result in what?
A sperm plug
What is special about the female chinchilla repro tract?
- have a postpartum estrus, Called a “breedback”
- have a vaginal closure membrane when not in estrus or parturition
Where can you collect blood from chinchillas?
- cephalic vein
- lateral saphenous vein
- cranial vena cava (this is traumatic and not recommended)
Major diseases/ailments of chinchillas (9)
- fur chewing/barbering
- malocclusion
- pododermatitis
- fur/hair ring
- dermatophytosis
- enteropathy/diarrhea
- pneumonia
- conjunctivitis
- trauma
What would cause a chinchilla to fur chew/barber?
Where does it typically start?
How can you alleviate it?
- stress!!
- starts over the hindquarters and back
- remove the cause of stress, introduce novel toys to distract
What typically causes malocclusion?
What are signs ass. W/ malocclusion
How can you dx?
How can you tx?
- inappropriate diet or chewing surfaces
- wet chin, chest, and paws; pawing at the mouth; weight loss; dysphasia; anorexia
- oral exam under sedation, skull rads
- trimming (usually recurrent)
Elongation of tooth roots can occur in chinchillas. Where can they extend?
What other signs can you see?
- how can you tx?
- what’s the prognosis?
- through the eye orbit, nasolacrimal duct, nasal cavity, and sinuses
- same signs as malocclusion, plus wet/runny eyes, exophthalmos, damage to nasolacrimal ducts
- palliative tax, long-term pain relief and syringe feeding
- poor prognosis
What can cause pododermatitis (aka bumblefoot)
Lack of solid, dry surfaces to rest on
Clinical signs of bumblefoot
- bottoms of back feet are swollen, dry, cracked, warm to the touch +/- abs cessation and bleeding
Tx of bumblefoot
Abx and drainage (if needed)
Chlorhexidine foot soak
Change the bedding to something softer or give solid resting areas
Topical ointment of Vit. E or Bag Balm
What is hair ring
Fur becomes matted around the penis when inside the prepuce
How might a hair ring chinchilla present?
Paraphimosis (unable to retract penis back into prepuce)
Excessive grooming
To of hair ring
Gently remove hair ring with lube
What is the most common skin disease of chinchillas
Is it zoonotic?
Dermatophytosis (ringworm)
Immensely
Causes of dermatophytosis
- trichopyhyton spp. Or microsporum spp.
Signs of ringworm
Hair loss, scaly, circular red patches typically on face/nose, but can be found elsewhere
Tx of ringworm
Topical anti fungal foot powder, germicidal/fungicidal spray, oral/topical griseofulvin
What are some safe abx to use for chinchilla abx-associated enterotoxemia
TMS, chlormaphenicol, enrofloxacin
T/F enrofloxacin can cause GI disturbances if given orally in chinchillas
True, use judiciously
What can cause enteropathy/diarrhea/GI stasis in Chinchillas
Abrupt changes in diet, low dietary fiber/high dietary energy, stress
How do you treat enteropathy/diarrhea/GI stasis in chinchillas
Replace fluid deficits, provide nutritional support, pain meds, SQ abs if indicated, NOT ORAL (GI flora upset)
Things to note re: trauma in chinchillas
Limb fractures
- don’t tolerate splints/external stabilization
- amputation may be necessary, do very well post-op
Tail injuries
- degloving common
- fur can be slipped form tail just like the body
- some tails are curly, some are straight, some are kinked—> all are okay
What are the major differences between Hystricomorphs and Myomorphs
- hystricomorphs have a longer gestation period
- hystricomorphs produce precocious young at birth
- hystricomorphs have a cellular membrane that closes over the vaginal opening except during estrus and at parturition
What species are hystricomorphs
Guinea pigs, chinchillas, nutria
Which species are myomorphs
Hamsters, gerbils, rats, and more
Guinea pig history
- domesticated by Bolivian and Peruvian indigenous populations for food
- brought to Europe in the mid-1500s by Spanish explorers
- most lab strains derived from animals produced by Dunkin and Hartley English stock in 1926
Biomedical Research uses of Guinea Pigs
- pregnancy toxemia, Ketoacidosis
- Scurvy (Vit. C deficiency)
- tuberculosis
- ulcerative colitis
- juvenile diabetes
- anaphylaxis
- delayed hypersensitivity
- nutrition
- amoebic diseases
- optic nerve problems
- leukemia
- auditory function
Breeds of Guinea Pig (and physical descriptions)
- English/American —> smooth, short hair, variety of colors
- Abyssinian —> rosette or whorled hair pattern, face and eyes are typically clear/not overgrown, variety of colors
- peruvian —> long Silky hair
- hairless —> very short to no hairs
Anatomy of guinea pigs
- prominent incisor teeth w/ premolar teeth**
- stocky bodies w/ no tail
- short legs —> 4 digits on forefoot, 3 on hindfoot
- mouth does NOT open very wide
- LARGE cecum present, with Taeniae —> 15-20 cm long
- GALL BLADDER PRESENT**
- both males and females have a pair of inguinal mammae (don’t assume female bc its there)
- males have an os penis, with two styles (points on tip)
How much of the GI tract does the cecum take up in guinea pigs
65%!!!!
Guinea pig behavior
- very vocal, very social and group around male
- little chicken shits (will freeze in response to motion)
- paranoid fuckers (very suspicious of strange/new objects)
- they’re like old geezers (establish rigid habits, dislike change)
- food preferences established early
- may stampede/trample young if frightened (“screw you baby, I’m out!”)
Guinea Pig nutrition
- strictly herbivorous
- ad libitum food and water
- 6 g food/100g BW per day, 10-40ml water/100g BW per day
- use bottles cuz they play in water
- feed guinea pig pellets, grass, hay, limited veggies
- COPROPHAGES
- NEED VITAMIN C!!! (15-25 mg/kg/day)
Guinea Pig Housing
- use solid bottoms/floors —> wire bottoms cause bumblefoot, and leg and toe injuries
Bedding
- acceptable: B&W newspaper, shredded paper, non-pine wood shavings, corn cobs, straw
Unacceptable: cedar, sawdust (clump)
Change bedding FREQUENTLY
Ideal temp: room temp (72F)
Sexing of guinea pigs
- digital pressure to extrude the penis in males
- females have a “Y” shaped opening
DON’T USE ANOGENITAL DISTANCE TO DETERMINE GENDER
T/F Guinea pigs have a vaginal closure membrane
True, only opens just prior to estrus, then closes and doesn’t reopen until parturition
Why is it important to breed guinea pigs and deliver her litter prior to first 6-8 months of age?
Failure to do so will result in permanent fusion of the pubic symposia, which “relaxes” and separates prior to parturition to increase birth canal diameter.
Estrous cycle of guinea pigs
~16 days, Estrus lasts 8-11 hours
- vaginal closure membrane open 2-3 days (before and during estrus)
Guinea pig gestation facts
- gestation: 59-72 days (avg 68)
- postpartum estrus occurs 12-15 hrs after birthing
- wean at 14-28 days
- young are precocious
- M sexually mature @ 8wks, F @ 5wks
