Hamsters Flashcards
What is the taxonomy of hamsters?
Order: rodentia
Suborder: myomorpha
Family: critetidae
Sub-family: circetinae
Genera: mesocricetus (main one), criteus, cricetulus, phodopus, tscherskia
What is the most common species of hamster seen in practice? What are some other species seen?
Syrian (golden) hamster (mesocricetus auratus)
- has many color variations
- there is an angora (or teddy bear) long haired variety
Other species: siberian (russian), european (black belly), armenian (grey), chinese “dwarf”, and long tailed
What is unique about the black belly hamster?
3X the size of other hamsters, has a black belly (duh)
-primary species sold in Europe
Describe the general history of hamsters
1930- one female with offspring taken from Syria to Israel and bred, almost all syrian hamsters originate from this original stock
1931- first syriann hamsters taken to britain
1938- first syrian hamsters taken to US (to east coast)
1948- first chinese hamsters shipped to US (to west coast)
1960s- several inbred strains of syrians were developed for research
What type of research were hamsters used for?
Dental, cancer, immunology (xenotransplants), infectious disease, hypothermia, parasitic disease, teratology, repro, vascular physiology, genetics (DCM)
-used more for research before they enters pet trade industry
How long is the adult hamster? How much do they weigh?
5-7 inches long
-50-150 g
What is the average lifespan of a hamster?
2-3 years
How much urine do hamsters produce on average?
5.4-8.4 mL/day
-AKA a lot
-have to change cage bedding frequently (2X per week at least)
Describe the basic anatomy and physiology of hamsters
-short tailed, short haired
-short blunt nose with small, rounded ears
-most with dark eyes, some with red (albinos)
-cheek pouches present which can evert
-stomach has a proximal non-glandular portion and distal glandular portion
-large cecum, cecal fermenter, coprophagic (can be source of bacteria after antibiotic use), sensitive to antibiotics
What exotics formulary was recommended?
Carpenters
What is the function of the cheek pouches in hamsters?
Used to transport feed and nesting material
-these are an immunopriviledged site
-these can be everted- must sedate them
Describe the teeth of hamsters
-prominent incisor teeth
-same dental formula as rats and mice
-molars do not grow continuously
What is the difference between the stomach of hamsters compared to rats and mice?
There is a greater demarcation between the non-glandular and glandular portions of the stomach
What occurs when you give antibiotics to hamsters?
Ileus and diarrhea
Describe the flank sebaceous glands of hamsters
-patches located on the flank
-they are present in both sexes, but only functional in males
-involved in marking territory and mating behavior
-secretion causes the hair in the flank area to become wet
Describe the behavior of hamsters
-borrowers in the wild- require materials to do this (paper towel rolls, PCV piping)
-crepuscular activity (most active in mornings and evenings)
-deep sleepers and can become aggressive when disturbed
-females often more aggressive than males
-permissive hibernators at temps <48 degrees
-escape artists that do not return to cage
Describe the diet of hamsters
-omnivores
-eat multiple times a day (need to be given food ad libitum as well as water-they drink and urinate a lot)
-coprophagous- provides source of vitamin B and K
-lab diets are nutritionally balanced (but should provide them a variety of foods so they dont get picky)
*dont know specific nutrient requirements
What is the ideal temperature for a hamster?
70-72 degrees
-dont need special temps- do well at room temp
How can you improve the enrichment of hamsters?
-plenty of cage room with a running wall/wheel (dont give wire wheels as they can predispose to pododermatitis)
-they have a circadian rhythm with daily bursts of energy
How should you restrain hamsters?
-cupping in hand or towel
-grip on scruff of neck and back (be aware they have a lot of skin, mobility of head is extreme)
-always support their bottom
How can you easily gender hamsters?
Anogenital distance
Describe the reproduction of hamsters
-4 day estrous cycle
-estrus (heat) starts at night
-post ovulatory discharge on the 2nd day
-females in estrus will exhibit lordosis 8 hrs before ovulation
-gestation is 15-18 days (shortest of all lab animals)
-litter size of 4-12 pups
-females may cannibalize pups if disturbed (stress response)
Describe neonatal development of hamsters
-birth weight of 2-3 g
-born hairless with eyes and ears closed
-ears open at day 5
-begin eating solid food on day 7-10
-hair starts emerging on day 9
-eyes open on day 15
-weigh 35-40 g at weaning
-weaning at 17-21 days
-can sex them at 5-7 days (should try to separate them early to prevent breedings in the future)
What are the options for collecting blood from hamsters?
Jugular, cephalic, retroorbital (not very humane), saphenous, mandibular, toe nail clip (not appropriate)
- maximum volume of 0.8-1 mL
Mandibular or saphenous recommended under sedation
Describe proliferative enteritis of hamsters
-aka wet tail
-caused by clostridium dificile mainly, but also lawsonia intracellularis, campylobacter fetus ssp jejuni, and E coli
-causes lethargy, anorexia, ruffled coat, typhlitis, diarrhea, dehydration and death
-often occurs post antibiotic therapy (most commonly), stress, poor diet, and recently weaned individuals
-lesion seen is hyperplasia of ileal epithelium
-transmitted by fecal oral route
-treatment: gentamycin- consider C/S testing
What are the main causes of pneumonia in hamsters?
Pasteurella pneumotropica, strep pneumonia and sendai virus (murine parainfluenza-hamsters are carriers but rarely show clinical signs)
-causes lethargy, anorexia, respiratory distress, nasal and ocular discharge
-trt: antibiotics
What are the primary tumors found in hamsters?
Malignant
- lymphosarcoma (viral induced, can affect skin GI or kindey - warts enteritis or pyelonephritis)
-reticulum cell sarcoma- lymph nodes
-carcinoma of intestine and adrenals
Benign-usually found post mortem
-gastrointestinal polyps
-adenomas of adrenal cortex
What is the primary cause of death in old hamsters?
Amyloidosis
- >85% occurrence in hamsters over 18 months
- etiology unknown
- causes anorexia, weight loss, PUPD, and proteinuria
-kidney is most common site of deposition
-occasionally amyloid in other organs (spleen, liver and adrenals)
What is tyzzers disease?
Caused by clostridium piliforme
-gram negative spore forming rod
-most common in mice
-stress induced disease
-clinical signs similar to wet tail (anorexia and weight loss, scruffy hunched up appearance, profuse diarrhea and dehydration)
-causes acute mortality with severe and/or bloody diarrhea and perianal staining (much more acute than wet tail)
Describe lymphocytic choriomeningitis
- a rodent borne viral disease (arenaviridae)
- more common in mice than hamsters
- virus spreads in urine, droppings, saliva and nesting material
- potentially zoonotic**- causes fever and muscle aches
- 2-5% of US human population has antibodies against this
-clinical signs in hamsters are variable, may include lethargy, anorexia, rough haircoat, weight loss, death
-can be infected for 8+ months, and may infect offspring
What are some of the internal parasites of hamsters
-giardia
-trichomononas
-spironucleus
-sympacia obvelata and s muris (pinworms- most commonly seen)
-hymenolepis nana and diminuta (tapeworms)
*hopefully not seen in pet populations as all are bred in captivity
What external parasites can be seen in hamsters?
