Rodents Flashcards
What are the big 3 classifications of rodents and what are some examples within each
-Caviomorphs: chinchilla, guinea pig
-Mymorphs: rats, hamsters, gerbils
-Sciuromorphs: chipmunks, squirrels
What are some general characteristics of rodents and rabbits
-Prey species
-Higher surface area to body mass ratio (lose body heat and dehydrate easily)
-Inguinal canal is open (close castration so dont get hernia)
-Postpartum estrus allows pregnancy immediately after birth
-Can’t vomit (esophagus meets stomach in middle)
What is the dentition of rodents and rabbits
-Elodonts
-Long crowns
-Aradicular (open rooted teeth)
-Grow throughout life
-4 incisors (rodents)
-6 incisors (rabbits,4 upper2 lower)
What does caeoctrophic mean
-Eat their own poop
In which species should you avoid penicillins (because of toxicity)
-Guinea pigs, hamsters, and chinchillas
-Only give parenterally in rabbits
Which species are hystricomorphs (caviomorphs) and what are some details about them
-Chinchilla, guinea pig, degu
-Herbivores (hindgut fermenters), like high fiber diet for teeth
-All teeth open rooted (20 teeth)
-Precocious young (well developed young, independent)
-Long gestation
What are the gestation lengths and lifespan of guinea pigs, chinchillas, and degu
-Guinea pig: 63 day gestation, 5-7 year lifespan
-Chinchilla: 111 days, 10+ years
-Degu: 90 days, 5-9 years
What species are myomorphs and what are some features of them
-“Mouse like” species (mice, rats)
-Altricial (very undeveloped young)
-Gestation 3-4 weeks
-Incisors elodont (grow always)
-Molars brachydont (stop growing at 3 months)
What species are sciuromorphs and what are some features of them
-“squirrel like” (squirrels, chipmunks)
-Altricial young
-Gestation 30 days
-Elodont incisors
-Brachydont molars
-Hibernation
How much blood can you take from rodents and where can you take from in caviomorphs
-1% of body weight (never more)
-Can take from jugular, saphenous, cranial vena cava (under GA), ear vein
Where can you take blood from in myomorphs
-Lateral tail vein, saphenous, tail artery in rats
Where are some injection sites in rodents
-Subcutaneous (fluids, not in guinea pigs because odor scruff)
-Intraperitoneal
-Intravenous
-Avoid IM as painful
Which route should you give fluids to a rodent with mild, moderate, and severe dehydration
-Mild: oral, subcut
-Moderate: intravenous (or intraperitoneal)
-Severe: intraosseous
What nutrition sources are good for chinchillas
-High fiber for teeth
-Long pellets
-Food that they can hold in paws
-Small oral cavity so small food items
How does dental malocclusion occur in chinchillas and what dental issues can it cause
-Incisors are usually equal in length, if one or the other elongated can cause malocclusion
-Can cause molar coronal elongation, sharp spurs, periodontal disease
What are clinical signs of dental malocclusion and disease
-Slobbers due to pain, wet chin
-Anorexia
-Rapid weight loss
-Chronic epiphora (eye discharge, maxillary root pressing eye)
-Gut stasis
What are some skin problems of rodents
-Fur slip: an escape mechanism where animal leaves patch of fur behind if grabbed too hard
-Matted fur: need dust baths
-Fur chewing: if lack of fiber in the diet
-Fur ring: hair tangled on penis
-Slobbers/wet chin: check teeth
What are some anatomical features of guinea pigs
-1 pair of nipples
-Pubic symphysis (closes around 11 months, can lead to dystopia if not bred before 1 year old)
-Vesicular gland
-Single cervix
What diet should guinea pigs be on
-Herbivore diet
-Need Vit C daily (10mg/kg) or can get scurvy
-Give pellets, hay, and vegetables daily
What are clinical signs of scurvy in rodents
-Lameness
-Dental malocclusion
-Weight loss, rough coat
-Ill thrift
-Sudden death
How many teeth doo guinea pigs have
20
How does tongue entrapment occur in guinea pigs
-Lower CT 1 and 2 arc over tongue
-These teeth elongate caused by lack of fiber and vit C
-Cause anorexia, weight loss
What is the relationship of upper and lower incisor size in guinea pigs
-Lower incisor is twice as long as upper incisor (normally)
-If upper incisors get too long, can cause pain and lower jaw rotation
What is done in dental surgery of guinea pigs
-Restoration of normal tooth length, restoration of the normal sloping occlusal plane, extraction of diseased teeth and treatment of any associated abscessation
What causes pneumonia in rodents and what are the signs and treatment
-Bordetella
-Sudden death, abortion in sows, treat with non-penicillin antibiotics, fluids, assisted feeding
What causes sarcoptic mange in rodents and what are the clinical signs
-Trixacarus caviae mange mite (burrows deep so difficult to find on scrapes)
-Intense pruritis, erythema, scaling and crusting on dorsum
What is the treatment or sarcoptic mange in rodents
-Ivermectin .5mg/kg SC 7 days for 3-4 treatments
-Meloxicam .5mg/kg because very sore and itchy
-Vit C and improved nutrition
-Treat all in contacts
-Remove stress
What causes ringworm in rodents and how is it treated
-T. Mentagrophytes
-Do a culture and give itraconazole
What species are myomorphs and what are their young and teeth like
-Myomorphs include mice hamsters gerbils and rats
-Altricial young
-Lower incisors twice as long + brachydont molars (stop growing at 3 months)
What is the nutrition of myomorphs
-Omnivores
-Pellets, veg, protein
-Like gnawing
What is the most common disease in rats
-Murine pneumonia
What pathogens cause murine pneumonia in rats and mice
-Mycoplasma most commonly
-Strep pneumoniae
-Pasturella pneumotropica
-Sendai virus
-Sialodacryoadentis virus
What are the clinical signs and treatments of murine pneumonia
-Tachypnea, rough hair coat, hunched, weight loss, chattering, head tilt, can be fatal or subclinical
-Treatment: fluoroquinolones, doxycycline, cephalexins, azithromycin, O2/fluids, nebulizing/inhalers
What is chromodacryorrhea in rats
-Red tears (porphyrin)
-Usually underlying resp disease
Are mammary tumors worse in mice or rats
-Malignant in mice, 90% benign in rats but grow a lot in size
When do hamsters like to be awake and how many hamsters should you have at once
-Hamsters are nocturnal
-Hamsters are solitary
What causes proliferative ileitis (wet tail) in hamsters and what are the clinical signs
-Lawsonia intracellularis usually in weanlings stressed from transport to the shop or to their new home
-Clin signs: dehydration, anorexia, diarrhea, hunched up, abdominal pain, usually fatal due to underlying stress
What are the treatment options for proliferative ileitis in hamsters
-Older animals can be treated with subcut or oral fluids and enrofloxacin or trimethoprim
-Supportive feeding
-many survivors get secondary intussusception or rectal prolapse
What skin disease do hamsters get
-Demodectic mange
-Cutaneous lymphoma (scabs and scaling)
-Allergies
Why does cheek pouch prolapse occur and how is it treated
-Mainly dwarf hamsters fed oversized food
-GA, clean and replace pouch, place anchor suture w 4/0 monofilament, give liquid food for 1-2 days, start feeding smaller food
What are some other ailments of hamsters
-Proptosis of the eye: enucleate if eye no longer viable
-Trauma
-Fractures
-Pseudohibernation: people think its dead and bury it alive
What are some common ailments of gerbils
-Matted fur: too humid, give sand baths
-Tail degloving: happens when grabbed inappropriately, amputate tail
What are some issues that can occur to the ventral scent gland of gerbils
-Infection
-Neoplasia (SCC, tend to remove with great success)
What is nasal dermatitis in gerbils
-Aka “gerbil nose”
-Gerbils dig with their noses, get sore and raw if too much digging or digging too rough of substances
What species are sciuromorphs
-Chipmunks, squirrels, prairie dogs
What issues can chipmunks get and how do we examine them
-Fighting injuries (often need ABs), human flu is fatal to them
-Examine under GA
