exam 3: mammals Flashcards
Lagomorpha
an order that includes leporidae which are the domestic rabbits, hatres, brush rabbits, and others
Rodentia
Includes
Caviidae: domestic guinea pigs, cavies maras, capybaras,
Muridae: rats, mice, gerbils
Carnivora
an order that includes Mustelidae (ferrets, weasles, polecats, wolverine, otters, badgers, others)
Oryctolagus cuniculi
the domestic rabbit that has many breeds
exclusively herbivores
hindgut fermenters
continuously growing incisors, premolars, and molars
unique dentition compared to rodents
Domestic lifespan of 8-12 years
What is special about rabbit’s eyes?
fewer corneal nerves, decreased sensitivity - have a bad menace because they evolved in the grass
What is special about rabbit’s ears?
they have a large surface area, assist with thermoregulation
also lop rabbits are predisposed to stenotic ear canals and secondary ear infections
What is special about rabbit’s respiratory system?
obligate nasal breathers, small thoracic cavity
-thymus persists into adulthood and is seen in x-ray
epiglottis sits above the soft palate
What is special about rabbit’s skin?
No foot pads, rely only on hair covering, prone to pododermatitis, do not shave feet
Why are rabbits elodont?
their teeth continuously grow (all teeth)
Why are rabbits hypsodont?
they have a long crown above the gum line.
Why are rabbits considered aradicular?
they have no root, classified as apex (apices)
Diastema
what separates the incisors from the cheek teeth (premolar and molars)
What is the rabbit’s dental formula
I 2/1, C 0/0, PM 3/2, M3/3
Peg tooth
referring to I2 (two maxillary incisors seen in the rabbit)
Rabbit Gastrointestinal anatomy
The complex GI tract that is reliant on hindgut fermentation
-Feeding unique microbiome of cecum
-Anarobes, aerobes, gram + and gram -
Require large amounts of large particle, non-digestible fiber
Produce and ingest cecotrophs “night feces”
-Different composition than regular fecal pellets
-Contain enzymes, amino acids, vitamins
*Need to be very careful about antibiotic selection
Cecotrophs
night feces that is a different composition than regular fecal pellets, contain enzymes, amino acids, and vitamins
Can rabbits vomit?
NO, they have a lower esophageal tone, do not need to fast prior to anesthesia
their stomach never empties
What part of the rabbit’s GI tract holds the largest volume?
Cecum
What is the function of the rabbit’s small intestine?
it has peyer’s patch for immune function and it absorbs nutrients from the cecotrophs
Sacculus rotundus
present in the rabbit’s GI tract. lymphoid tissue at the ileocecocolic junction that is a round outpouching with lots of lymphoid tissue
Rabbit cecum
holds the largest and most volume of the GI tract
Haustra (sacculations
Mixed contents- fluid and short particle fibers
Microbial fermentation produces volatile fatty acids
What is the function of the rabbit’s large intestine
the proximal and distal colon separates fiber sizes and forms fecal pellets
Fusus coli
ganglion cell aggregates that are the pacemaker that determines the fecal excretion and cecotropes vs normal feces.
What is unique about rabbit’s urine
it may be cloudy with calcium or pigemented (plants, porphyrin)
Because of this primarily renal excretion of Ca this makes them more predisposed to urinary stones or calcium sludge
Blood calcium is not tightly regulated; reflects dietary calcium consumption
Characteristics of Rabbit reproductive tract
Two cervices,
predisposed to uterine adenocarcinoma
induced ovulators, do not go through estrus
Babies are altrical
Testicles are cranial to the penis
Cavia porcellus
the guinea pig, many breeds
exclusively herbivores
hindgut fermenters
continuously growing incisors, premolars, and molars
require exogenous vitamin C
Domestic lifespan of 6-8 years
What is special about guinea pig eyes?
they develop benign changes
Pea eye- fat deposits ventral to the eyes
Osseous metaplasia- calcified ring around the limbus
What is special about guinea pig respiratory system?
they are obligate nasal breathers
and have a palatal ostium (do not intubate)
epiglottis sits above the soft palate
What is unique about the guinea pig anus?
it is flaccid
males are prone to “boar butt” = fecal impaction
early neutering may reduce the boar butt
Guinea pig dentition
Elodont, Hypsodont, aradicular
I 1/1, C0/0, PM 1/1, M 3/3
When overgrown, mandibular cheek teeth can grow over tongue
Dietary fiber (and silica content) is essential to wear teeth down
-Pellets do not serve this function
Do guinea pigs rely on cecotrophs?
No but they do practice coprophagy
Coprophagy
the art of eating feces
Do guinea pigs vomit?
No they do not but they can passively regurgitate under sedation/anesthesia
What is special about the microflora of guinea pigs?
It is mostly gram + microflora
Why are guinea pigs predisposed to scurvy?
they lack the enzyme to convert endogenous precurso into ascorbic acid (vitamin C)
-Must be supplemented externally through special pellets with added vitamin C or veggies (red pepper, kale, parsley, or treats)
What are some signs of scurvy in guinea pigs?
they have dry flaky skin and fur loss
gingival disease, loose teeth
joint hemorrhage, swelling
Why are guinea pigs predisposed to urinary stones and obstruction?
they have a smaller urethra and also secondary have high calcium in the diet
Why are guinea pigs predisposed to dystocia?
there is the fusion of pubic symphysis, large babies, and obesity
not related but also prone to ovarian cysts
Are newborn guinea pigs precocial or altrical?
precocial- big babies
Rattus norvegicus
the rat
omnivores
have a partial hindgut GI tract (large cecum)
Elondont incisors (continuously grow), anelodont brachydont cheek teeth
Live 2-3 years
What is special about rodents reproductive system?
they have rapid reproduction with large litters, tend to develop reproductive neoplasia
Rodent dentition formula
I 1/1, C0/0, PM0/0, M3/3
Elodont incisors, brachydont cheek teeth which dont need to be trimmed
Pigmented rostral surface of incisors (iron)
fibrous mandibular symphysis with mobility
Rostral-caudal gnawing motion
Rodent GI physiology
a simple monogastric stomach, cannot vomit but does regurgitate
a well developed cecum
*Do not utilize hindgut fermentation
*Do not require long non-digestible fiber
*Do best on block diet consisting of grain mix
*Prone to obesity
Mustela putorius furo
exclusively carnivores
Simple monogastric GI tract
enlarged anal scent glands
domestic lifespan of 6-8 years
Why are ferrets predisposed to developing cancers like insulinoma, adrenal tumors, and lymphoma in the US
a small genetic population and inbreeding
ferret lifestyle
they are very active, curious animals (prone to ingesting foreign material and obstruction) will dog and burrow (destroys furniture)
social thrive in groups
tend to gain weight and a thicker coat seasonally “winter weight”
Ferret dentition formula
I3/3, C1/1, PM3/3, M1/2
Ferret basic diet
exclusively carnivores, like cats
require high protein >30%
Rapid GI transit time 3-4 hours
Commercial kibbles available that meet all nutritional standard
raw can meet nutritional needs but pose a human safety risk, difficult to balance properly
What are some infectious diseases that ferrets can get?
-Influenza from humans, COVID-19, distemper, helicobacter mustelidae, viral coronavirus diarrhea- epizootic catarrhal enteritis
Hystricomorph Rodents
Chinchillas, guinea pigs, degus
Do guinea pigs develop their preferences early in life?
Yes, they do
Supracaudal gland
a gland in guinea pigs that can get crusty and stinking in guinea pigs
Keratin horn forepaws
a feature on the guinea pig paw that can be trimemd like nails
Hairless patches in guinea pigs
medial aspect of the forelimbs and caudal to the pinna
Palatal ostium
fused caudal laryngeal tissues that makes it more difficult to intubate guinea pigs, hole inside a hole
Guinea pig teeth are
elodont, aradicular, and hypsodont (same as rabbits and chinchillas
30 degree angle to occlusion surface vs 0 for chinchillas
Guinea pig/chinchilla dental formula
2 (I1/1, C 0/0, PM 1/1, M 3/3) = 20 teeth
*all are continuously growing
What is the predominate bacteria in Guinea pigs?
Lactobacilli
What is the predominate bacteria in rabbits?
bacteriodes
Guinea pig pelvic symphysis
fibrocartilaginous and a gap can be palpated at impending parturition
-separates entirely near parturition
Can male guinea pigs get mammary cancer?
Yes
Guinea pig gestation period
63-65 days (like a dog)
Guinea pig repro
suspensory ligament is really tight, hard to stretch when spaying, challenging to do a midline spay, go across on the flank
*Have a uterine body and a single cervix
Scotal outpouching
present in male guinea pigs, have open inguinal ring about to invert testicles, migrate in and out of the body
Epididymal fat
present in the male guinea pig, extends into the abdominal cavity and prevents intestinal herniation
presence of os penis
need to make sure to ligate vaginal tunic when nuetering
What accessory sex glands for male guinea pigs have?
All of them
-Prostate
-Bulbourethral
-Coagulating Gland
-Seminal vesicles (sometimes look like uterine horns in ultrasound)
What substrate should you not use for guinea pigs?
Cedar and pine (very aromatic and oily)
use aspen shaving instead
Why should you not house or allow interactions between guinea pigs and rabbits (also dogs)
guinea pigs carry Bordatella Bronchiseptica
Chinchilla lanigera
chinchillas, hystericomorph rodents from south america
not different breeds, just different coat colors
eat and defecate mainly at night
sometimes do better in groups
How long do chinchillas live?
10-15 years but up to 22 years reported
Chinchilla hair coat
very soft and dense- up to 60 hairs from one follicle
Why are eye exams hard on chinchillas?
they have a vertical pupil
Do you need to trim chinchilla nails?
NO
What is the bristly fur on the pelvic feet used for?
grooming
How many pairs of mammary glands do chinchillas have?
one inguinal and two later thoracic pairs
Do chinchillas do dust baths
daily to several times per week
if too much can lead to dry skin, conjunctival and respiratory irritation
make sure you use special chinchilla dust *not dust from outside
Octodon degu
a hystricomorph rodent from chile
similar to chinchilas
open inguinal rings = complicated castration
prone to fur slip and tail slip
Guinea pig nutrition
Require dietary source of vitamin C
-commercial supplemental
-Pellets
-Vegetables: focus on vitamin C rich options
-Water supplementation is not reliable
Chinchilla and degu nutrition
similar to guinea pig nutrition, but have higher nutritional needs, need a small amount of alfalfa in their either either through hay or pellets
Can still offer greens, still avoid fruits, seeds, and carbohydrates
Mustela putorius furo
domestic ferrets
mustelidae (most are solitary, nocturnal, and active year round
Anal scent glands
obligate carnivores
domestication history is unclear
Domestic uses of ferrets
1) Rodent and Rabbit control- efficient predators, bring down prey larger than themselves, maneuver small spaces more effectively than cats
2) Sport of ferreting
3) Entertainment: ferret-legging
4) Transport cables through conduit
5) Biomedical research
6) Companion/pet
Domestic ferrets as pets
-no breeds, but many colors/patterns (panda + blaze have a higher prevalene of deafness and more apt to bite)
-majority of ferrets in the US will be afflicted by one or more neoplastic diseases as they age (lymphoma, insulinoma, adrenal disease)
-Inquisitive, playful
-Not suitable for children <6 years old
-Beware of bite (not the best eyesight)
-Legal issues with ownership (can see ferrets despite if they are illegal in the state)
Typical North American Ferret
Large breeding facilities (Marshall Farms)
Tattoos (surgical sterilization and descended) *marks
Smelly: anal glands vs being a mustelid
“Fully” vaccinated - one vax (Rabies, Canine Distemper)
Ferret Coat
Coat: heavy shed in the spring and fall
Shorter/darker in the summer; longer/lighter in the winter
Sexually altered = less dramatic molt/color change
Where does the majority of ferret smell come from?
sebaceous glands
Ferret anal glands
contain foul smell material, located at 4 and 8 oclock positions around the anus, nodular glandular complex around neck and duct
Ferret GI
Female ferret (jill)
induced ovulators, during estrus, vulva swells considerably, adrenal disease can cause vulva swells too
Male ferret (hob)
like a dog, with the exception of J-shaped os penis
important clinically, because of the catheter placement
surrounds proximal urethra
adrenal disease affects its size too
Ferret diet
-Most common: kibble (totally ferrett, mazuri ferret, marshall farms)
-Supplement to kibble: canned diet
treats: often comproised of cereals/sugars (avoide, use meat based or Ferretone instead
