Other rodents Flashcards
Is IACUC oversight needed for field study that doesn’t harm or materially alter behavior according to AWA and PHS policy?
AWA: exempt
PHS: any field study needs IACUC
Species in suborder Sciuromorpha, family Sciuridae
Ground squirrels (Ictidomys – Thirteen-lined Ground Squirrels
Urocitellus – Richardson’s ground squirrel
Spermophilus - other ground squirrels)
Prairie dogs (Cynomys)
Woodchuck (Marmota)
Chipmunks (Tamius)
Genus in suborder Sciuromorpha, family Heteromyidae
Kangaroo rat (Dipodomys)
Genera in family Myomorpha, family Cricetidae
Pack rats (Neotoma)
Grasshopper mice (Onychomys)
Deer mice (Peromyscus)
Rice rat (Oryzomys)
Cane Mice (Zygodontomys)
Cotton Rats (Sigmodon)
Hamsters
Voles (Microtus)
Genera in family Myomorpha, family Muridae
Gerbils (Meriones)
Mice
Rats
Multimammate mice/rats (Mastomys)
Rodent families are differentiated based on…
the attachment points of masseter muscle
Which rodents are hibernators and at what temperature is hibernation induced?
Ground squirrels and Prairie dogs (5-10C)
Also Woodchuck, European hamster
Which rodents are induced ovulators?
Voles (Microtus)
Degu (Degu)
Woodchuck (Marmota)
Which rodents are have precocial young
Guinea pigs
Chinchillas
Degu
Spiny mouse
Which rodent has the longest gestation length?
Chinchilla (genus Chinchilla) - 111 days
Which rodent is carnivorous and can be fed fresh mouse carcasses in the lab?
Grasshopper mouse (Onychomys)
Which rodents have a very high metabolic rate and develop hypoglycemia if fasted for 6 hours?
Voles (Microtus)
Which rodent, like the woodchuck, develops HCC secondary to Hepatitis B virus?
Ground squirrels
Ground Squirrel Hepatitis Virus (GSHV) - Hepadnaviridae like Hepatitis B Virus
Which rodents maintain a “rotating pasture” in the wild?
Prairie dog (Cynomys)
Which rodent was responsible for the 2003 monkeypox outbreak and had contracted infection from Gambian pouched rat (dormouse also a reservoir)
Prairie dog (Cynomys)
Which rodent is used to study biliary physiology as it has an easily-accessible gallbladder?
Prairie dog (Cynomys)
Which rodent is highly susceptible to Fransicella tularemia? What BSL is used to study?
Prairie dog (Cynomys)
House @ BSL2
Nx @ BSL3 b/c TM resp
Which two rodents commonly develop elodontoma in response to mechanical trauma of incisors and presents with upper resp signs?
Prairie dog (Cynomys)
Degu (Octodon)
Which two rodent species exhibit host switching for Eimeria?
Prairie dogs (Cynomys) and ground squirrels
Which rodent can die from exhaustion if given only soil substrate (need some kind of tunnel system)?
Gophers (Geomys = eastern gopher, Thomomys = western gopher)
Which rodent is useful to study parasite-host relationship (b/c solitary lifestyle and transmission rate low)?
Gophers (Geomys = eastern gopher, Thomomys = western gopher)
Which rodent cannot have ad lib water or it will develop diabetes insipidus-like condition? Which rodent is prone to diabetes mellitus?
Kangaroo rat (Dipodomys)
Degu (Octodon)
Which rodent is used to study renal physiology and water conservation?
Kangaroo rat (Dipodomys)
Which rodent is used to study decompression sickness (response to environmental pressure is similar to humans)?
Kangaroo rat (Dipodomys)
Which two rodents develop spongiform degeneration of the central auditory system (Most commonly in animals continually exposed for extended periods to low frequency sound <75dB)?
Kangaroo rat (Dipodomys)
Gerbil (Meriones unguiculatus)
Which two rodents have enzymes protective against rattlesnake venom?
rock squirrel (Spermophilus beecheyi)
southern-plains wood rat (Neotoma micropus)
Which rodent develops age-related Chronic glomerulonephropathy similar to chronic progressive nephropathy in rats?
captive wood rats (Neotoma)
Which rodents require dust baths?
Chinchillas, Degu, Kangaroo rats, Grasshopper mouse, Gerbil
Which rodent preys extensively on scorpions and resistant to scorpion envenomation?
Southern Grasshopper Mouse (Onchomys torridus)
Which rodent has been successfully cross-fostered onto Peromyscus?
Southern Grasshopper Mouse (Onchomys torridus)
Which rodent is a null model for Yersinia pestis (plague) and is highly resistant?
Grasshopper Mouse (Onychomys) - likely bc carnivorous which promotes selection of plague resistance
Which rodent can transmit Borrelia burgdorferi via urine?
Grasshopper Mouse (Onychomys)
Which rodent displays idiopathic convulsive seizures in a captive colony similar to gerbils?
Grasshopper Mouse (Onychomys)
Scientific name and gestation length for white-footed mouse
Peromyscus leucopus
Gestation: 22-23 d
Dental formula Peromyscus leucopus
I1/1, C 0/0, PM 2/1, M 3/3
Peromyscus leucopus use in research
T2DM, cataracts
Genetics, physiology, aging, behavior
Lyme
Permissive to Hantavirus (Sin nombre virus)
Hyperlipidemia inducible by high fat diet (heritable)
Which center distributes Peromyscus for use in research?
Peromyscus Genetic Stock Center (PGSC) @ U South Carolina
Which rodent has multiple chromosomal polymorphisms like Aotus?
Rice rat (Oryzomys)
46-56 chromosomes
Which rodent is infected with the Spiny rat louse (Polypax spinulosa)?
Rice rat (Oryzomys)
Which rodents are permissible/carry the hantaviruses?
Peromyscus, pack rats (Neotoma) - Sin Nombre virus
Oryzomys (rice rat) - Bayou virus; develop kyphosis
Rattus rats carry Seoul Virus (cause of Hemorrhagic and Renal Syndrome)
Sigmodon (cotton rat) - Black Creek Canal virus
Which rodent is a natural host of Guanarito virus – Venezuelan hemorrhagic fever (VHF), which is zoonotic?
Clinical signs?
Cane mice (Zygodontomys brevicauda)
chronic viremic infxn w/ persistent shedding in oropharyngeal secretions and urine
How to handle Cotton rat (Sigmodon)?
NOT BY TAIL
Scruff around neck and use leather gloves
Which rodent is a model for viral respiratory diseases e.g. Respiratory Syncytial Virus (RSV, Paramyxoviridae)?
Cotton rat (Sigmodon)
Also parainfluenza 3 and Measles
Which rodent is a the only animal model for human epidemic KCS secondary to ocular adenovirus infection?
Cotton rat (Sigmodon)
What diseases are cotton rats (Sigmodon) natural reservoirs for?
Lyme disease, Black Creek Canal virus (hantavirus), & VEE
Which rodent develops Gastric tubular adenocarcinoma (adult females)?
cotton rats (Sigmodon)
Which rodent has a rudimentary prostate in females, gestation 38 days, 2 pairs of inguinal mammae, are monogamous, and newborns attach firmly to the nipples of the dams and are dragged about for 3 weeks?
White-Tailed Rat (Mystromys)
Which rodent is reservoir/model for Leishmania braziliensis (American cutaneous leishmaniasis), donovani, and mexicana?
White-Tailed Rat (Mystromys)
Vaccination studies
Which rodent has rootless molars?
Voles (Microtus)
Also Guinea pig
Can get bad malocclusion
Which rodents are induced ovulators?
Prairie vole (Microtus ochrogaster)
How does sire affect pup development in different types of voles?
If sire stays around, pup development accelerates in Prairie vole (M. ochrogaster)
If sire stays around, this hinders pup development in Meadow vole (M. pennsylvanicus)
Which rodents can have up to 18 pairs of mammae?
Multimammate Rats (Mastomys)
Usually 8-12 pairs
Submaxillary salivary glands of ___ are richest available source of nerve growth factor.
Mastomys natalensis (multimammate rat)
Which rodent is the only non-human host of Lassa virus (Arenaviridae)?
Multimammate Rats (Mastomys)
Which rodents and chicken are models for Autoimmune thyroiditis (Hashimoto’s dz)?
Multimammate Rats (Mastomys)
Buffalo rats
Obese strain (OS) chicken
Which rodent spontaneously develops gastric ACA, a model for Zollinger Ellison syndrome?
Multimammate Rats (Mastomys)
Which rodent has splenic sinusoids lined w/ endo cells w/ cuboidal morphology?
Degu (Octodon)
Which rodent is used to study neuropeptides oxytocin and vasopressin and control over pair-bonding, maternal and paternal care, mate-guarding?
M. ochrogaster (prairie vole)
Which rodent is used to study African typanosomiasis?
M. montanus (montane vole)
Which rodent has blood supply to brain = only by vertebral arteries w/ no internal carotid ?
Degu (Octodon)
Chinchilla
Gestation of degu (Octodon)
90 days
Which rodent suborder have cornified penile spikes? Which species is induced ovulator?
Hystricomorpha (guinea pig, chinchilla, degu)
Degu induced ovulator; others spontaneous
Which rodent is diurnal and used to study Circadian rhythm and jet lag?
Degu (Octodon)
Which rodent is eusocial with one breeding queen w/ several non-reproductive workers?
Naked Mole Rats (Heterocephalus)
Which rodent has precumberent incisors extend beyond mouth to aid in burrowing (fossorial)?
Naked Mole Rats (Heterocephalus)
Vs Callitrichids procumbent
Which rodents are used to study aging and live up to 30 years?
Naked Mole Rats (Heterocephalus)
Which rodents have pain insensitivity?
Naked Mole Rats (Heterocephalus)
Which rodents are highly susceptible to Herpes simplex 1?
Naked Mole Rats (Heterocephalus)
Which rodents have palatium ostium, all teeth are open-rooted, precocious young?
Chinchilla (Chinchilla chinchilla)
Guinea pig (Cavia porcellus)
Which rodent has blood collection site: transverse sinus (top of head) –> up to 10 mL?
Chinchilla (Chinchilla chinchilla)
Which rodent is HIGHLY SUSCEPTIBLE to lethal infxn w/ hu Monkeypox virus (MPXV)?
Dormice (Graphiurus)
Additional reservoirs: prairie dogs (Cynomys), Gambian pouched rat
For which rodent are tail and foot pad sites for cutaneous leishmania (L. tropica)?
Egyptian Fat-Tail Jird (Pachyuromys)
Which rodent is important reservoir host of Leishmania tropica (transmitted by sand fly Phlebotomos sp)?
Sand Rat (Psammomys)
Mycoplasma volis, which was isolated from healthy field trapped Microtus ochrogaster, causes what in mice and rats?
Microtus ochrogaster = prairie vole
Seroconvert but no clinical signs
Which species will die if only given soil substrate, but can go without water?
Pocket gophers (Geomys and Thomomys spp.)
Name zoonotic diseases associated with grasshopper mice (Onychomys)
Yersinia pestis, Borrelia burgdorferi, Coxiella burnetii
Which rodent gets hyperlipidemia inducible by high fat diet (heritable)
Peromyscus
Which vole is monogamous?
Microtus ochrogaster (prairie vole)
What anesthetic ocular lesions in rats?
Ketamine/xylazine
Which coprophagic species is noted to specifically consume fecal pellets during the day because they have a higher nitrogen content?
Chinchilla
Chinchillas get heat stroke above ___F
80
Temp and humidity for Heterocephalus glaber
85F 50%
Which rodent is monogamous and used for role of neuropeptides oxytocin and vasopressin and control over pair-bonding, maternal and paternal care, mate-guarding
Prairie vole (Microtus ochrogaster)
Which rodents are models for T1DM and T2DM?
White-Tailed Rat (Mystromys) - historical model of T1DM
Sand Rat (Psammomys)
What are two species of chinchilla?
Chinchilla chinchilla: short-tailed chinchilla
Chinchilla lanigera: long-tailed chinchilla
both critically endangered
Use of chinchilla in research
Auditory
Upper respiratory infection
Hyperthyroidism
How often should chinchillas get dust baths?
prevents fur from becoming matted and greasy Dust baths should be provided for 15 min daily or several times a week
At what temp and humidity do chinchillas get heat stroke? Above what temp do they die?
How to calculate if concern for heat stroke based on temp and humidity
65–80°F (18.3–26.7°C)
temp >32°C (90°F) and if humidity of >60%
concern if temp + humidity > 150
Auditory similarities in chinchillas to humans and why chinchillas are a good model
Similar hearing range, thin-walled tympanic bullae making middle ear readily accessible, cochlea have 3 turns like humans, malleus and incus can move independently
What structure do guinea pigs and chinchillas (Hystricomorpha) have that’s important for intubation
palatal ostium
Which coprophagic species is noted to specifically consume fecal pellets
during the day because they have a higher nitrogen content?
Chinchilla
Which rodent has the longest gestation?
Chinchilla (111 days)
Ddx chinchilla drooling, retching, dyspnea, anorexia. Recently gave birth.
Esophageal choke
Common in animals that eat bedding or postparturient females that eat placentas
Chinchillas cannot vomit
What happens when chinchillas are not handled appropriately?
Fur slip –> leaves smooth area of skin
Vs fur chewing which causes moth-eaten appearance
Ddx and tx for conjunctivitis in chinchillas
Ddx: excessive dust bathing or dirty dust baths, dirty bedding, inadequate cage ventilation, underlying nasolacrimal duct obstruction, Pseudomonas aeruginosa as a localized infection or systemic infection
Tx: restricting dust bath access, lavage conjunctival sac, broad spectrum Abx ophthalmic ointment
What is most common congenital disease in chinchillas?
Malocclusion
Causes “slobbers”
Perforations in chinchilla cage flooring should be no larger than __ x ___ inch
1/2 inch x 1/2 inch
Which Clostridium perfringens type is most commonly environmental?
Type A
A granulomatous lesion is found in the liver of a chinchilla on necropsy. Which zoonotic bacterial list of differentials?
Yersinia pseudotuberculosis
Chinchillas are susceptible to which human virus?
Human herpes simplex virus 1
True or false: constipation occurs more often than diarrhea in the chinchilla
TRUE
Which bone is most likely to be fractured in the chinchilla?
Tibia
Tolerate amputation well
You encounter a male chinchilla that is grooming excessively, producing small amounts of urine, and straining to urinate. What do you suspect is the problem?
Fur ring
Genus species of woodchuck
Marmota monax
Use of Marmota monax in research
Hibernation (also ground squirrels, European hamster)
Viral hepatitis (woodchuck hepatitis virus WHV) - Hepadnaviridea like Hep B; cause of hepatocellular carcinoma
food intake, obesity, and energy balance, endogenous circannual cycles, photoperiod entrainment of circannual cycles, seasonal breeding
Gaps in enclosure cannot be more than ___ inches bc woodchucks will escape anything head fits through.
1.5 inches
Name of biocontainment enclosure for woodchucks infected with WHV
Horsfall cages (Illinois cubicles)
What to do for anesthetic prep and recovery for Marmota monax?
Prep: FAST. They can vomit unlike other rodents
Recovery: No water available. They will drown.
For which routine things is anesthesia needed for Marmota monax?
Abdominal palpation
Venipuncture
Hibernating inducing conditions for Marmota monax
food withdrawal or cold room 5-10°C
reduce room temperature to 15°C or lower and removing food
(same temp for ground squirrels)
Marmota monax gestation length
31 days
How to entrain the endogenous cycle of woodchucks to 12-month intervals by exposure to simulated natural
photoperiods?
Change photoperiod daily by up to 4 minutes per day w/ microprocessor controlled timer
Which sex and age of woodchuck emerge earlier from hibernation?
Males earlier than females
Adults before juveniles
Marmota monax can be fed the same diet as ___ with at least ___% protein
rabbits
15
When is repro season for Marmota monax? What type of ovulation?
In spring after hibernation will have a single litter
Induced ovulator
Distribution of fetuses in uterus of Marmota monax
All in one horn
Have double cervix; fetuses cannot spread between two horns
What types of placentation and implantation do woodchucks have (same as mice/rats)?
Discoid hemochorial placenta
Antimesometrial - Implant in lumen opposite uterine mesentery (mesometrium), away from mesentery and blood supply
Which prominent male sex gland in Marmota monax is responsible for urethral plugs during ejaculation and vaginal plugs in females after mating?
Bulbourethral (Cowper’s) glands
How to detect proestrus in Marmota monax
measure vulvar diameter
> 7 mm = proestrus
What is a non-infectious cause of pup mortality in Marmota monax?
Pup mortality d/t food competition during periweaning period (30-80d age) - provide two bowls
How to differentiate Marmota monax in torpor from illness?
Torpor: body temp close to room temp (as low as 8-10)
Sick: body temp slightly decreased (37C is normal)
Causes of bacterial folliculitis in woodchucks vs mice/rats
Woodchucks (most common derm dz!): stress, hormone changes, also poor husbandry
Mice/rats: moisture, wounds, crowding, high temps, low dietary protein
Coinfection with which bacterium is found in woodchucks with HCC? Is there sex predilection for HCC?
Helicobacter marmotae (similar to A/J mice with Helicobacter hepaticus but no sex predilection unlike mice where more prevalent/severe in MALES)
No sex predilection likely because male woodchucks are functionally castrated for at least 8 months of the year
What are molecular markers of HCC in Marmota monax?
alpha-fetoprotein
GGT
Marmota monax reservoir for which virus that is zoonotic and causes encephalitis in humans, can be fatal esp. children? How is it transmitted?
Powassan virus (Flaviviridae)
Ticks - Ixodes cookei
What diseases are transmitted to woodchucks by Ixodes cookei?
Powassan virus (Flaviviridae)
Ackertia marmotae, a nematode
Rocky Mountain Spotted Fever (Rickettsia rickettsii)
Lyme
Which two parasites are associated with liver lesions in woodchucks?
Ackertia marmotae
Capillaria hepatica
(both nematodes)
Name of trematode (called the lancet liver fluke) in Marmota monax? What is transmission and pathology?
Dicrocoelium dendriticum
Fluke eggs in feces of definitive host (usually sheep, cattle, deer, pigs, rabbits) –> ingested by snails (IH) –> cercaria develop and secreted in snail mucus –> ants eat mucus (2nd IH) –> woodchuck eat ants when grazing
Cirrhosis (seen in sheep, woodchucks)
Ddx white muscle lesions in woodchuck
Capture myopathy vs white muscle disease (Vit E/selenium deficienty) - pathology indistinguishable
What can happen to woodchucks with pressure to thorax during restraint?
Diaphragmatic hernia - have natural weakness in DORSAL portion of diaphragm
What are common causes of sudden death in woodchucks with no preceding signs?
Aortic rupture
Cardiomyopathy leading to CHF
Colonic strangulation from torsion
What is renal comorbidity of WHV in woodchucks?
Immune-mediated glomerulonephritis
Can see PLE and edema e.g. anasarca
3 types:
1. Membranous (more in younger animals, same w/ humans)
2. Mixed membranous and mesangial proliferation
3. Mesangial proliferative glomerulonephritis
What viruses are closely related to WHV
Hepatitis B
Ground Squirrel Hepatitis Virus - in multiple species of Spermophilus
All in Hepadnaviridae family
How is WHV replication similar to retroviruses?
transition of viral DNA to viral RNA
integration not required like for retroviruses but appears to play a role in development of HCC; in some cases integrating into c-Myc locus (proto-oncogene)
The possible interaction between hepadnavirus
infection and ____ toxin has been investigated using the woodchuck model.
Aflatoxin
The linguifacial vein can be used for blood collection in which rodent?
Woodchuck (Marmota monax)
Not to be confused with jugular vein (even though looks like you’re sticking the neck; they just don’t really have a neck)
How long should quarantine be for wild-caught woodchucks?
6 months
Woodchucks can be successfully maintained at
_____ - ____°C.
17–23
To reduce the chance of ringtail-like syndrome in woodchucks, humidity should be maintained at what percentage?
50%
What anesthetic administered IV will prolong ketamine/xylazine anesthesia?
Sodium pentobarbital
In BB mention administering in sublingual vein
Routine blood collection sites in Marmota monax
Femoral
Maxillary or linguifacial
Tarsal or cephalic (small volumes)
Sublingual not mentioned for routine blood collection
Innovar-vet (Droperidol) can be reversed with ____
naloxone
Hibernation in woodchucks is associated with ___ levels of free T4 and ___ levels of total T4.
Low; high
Most common bacteria cultured from bacterial folliculitis lesions in woodchucks?
Staph aureus, Group A Strep
What is the most common bacterial organism cultured from the lungs of woodchucks with pneumonia?
β-hemolytic Streptococcus sp
Most likely cause of CNS signs in wild-caught woodchuck
Rabies
Most like cause of nematode found in CNS of woodchuck?
Baylisascaris
What diagnostic test for Giardia trophozoites vs cysts?
Trophozoites: smear
Cysts: float
What is the pinworm found in woodchucks (but not associated with clinical signs)?
Citellina triradiata
Which parasite is found in the stomach of woodchucks?
Obeliscoides cuniculi
(common in wild woodchucks; natural host is rabbit)
Name of mite, louse, tick, and flea found in woodchucks
Mite – Androlaelaps fahrenholzi
Louse – Endeleinellus marmotae
Tick – Ixodes cookei
Flea – Orpsylla arctomys
Where is the most likely site of GI strangulation in the woodchuck?
Ascending colon - has 2 loops free in abdomen that can become entangled
Often found dead suddenly
The identification of the ___ antigen and the establishment of its relation to the virus of hepatitis B are among the most important medical discoveries of the twentieth century.
Australia antigen - indicates current or past infection with Hepatitis B
Which parasite interfered with early WHV work in wild caught woodchucks?
Ackertia marmotae (one of the nematodes that can cause liver lesions; other one is Capillaria)
How to establish chronic WHV infection in the lab?
Infection AT BIRTH with infected serum from chronic carriers
What are the suspected mechanisms of hepatocarcinogenesis associated with Hepadnavirus infection?
1) Integration of viral nucleic acid into host cell DNA and N-myc activation
2) Hepatic injury from the virus enhances spontaneous mutations etc and malignant transformation
3) Hepatic inflammation may cause nitric oxide carcinogenesis
Name species in 3 main suborders of rodents
Sciuromorphs: squirrels, woodchucks, gophers, beavers, geomyids
Myomorphs: mice, rats, hamsters, gerbils, voles
Hystricomorphs: porcupines, chinchillas, guinea pigs, degus, jerboas
Ground squirrels get dermatitis associated with infection w/ ___ and ___
C. ulcerans, S. aureus
What are two uses in research for Acomys?
Spiny mouse
1) Tissue regeneration
2) Born precocial (at late developmental stage)
Which rodent is used to study Alzheimer’s?
Degu (Octodon)
Which rodent has incisors splayed for first two weeks and latch onto mom’s teat and get dragged around?
Neotoma (pack rats)
What is the genus for giant pouched rats? What is use in research? What diseases do they get?
Cricetomys
Can be trained to detect things by olfaction
2003 monkeypox outbreak (also prairie dogs Cynomys)
Spontaneous pituitary neoplasms - prolactin positive staining
Granular lymphocytes
Which rodent should you do photoentrainment (change light cycle with season)
Woodchuck (Marmota monax)
Which rodent CAN vomit and should be fasted?
Woodchuck (Marmota monax)
