| Color Key | |
| Important key words or phrases. | |
| Important concepts or main ideas. | |
1. Learning Objectives and Review
1.1. Learning Objectives
- Understand the management of dental malocclusion in the guinea pig and chinchilla
- Know the importance of closing the inguinal ring in surgical castration of the male guinea pig and chinchilla
- Know the antibiotics that are safe to use in the guinea pig, chinchilla, and hamster and why this is an important issue
- Be familiar with the following diseases in the guinea pig
- Vitamin C deficiency
- Dystocia
- Lymphadenitis
- Be familiar with the following diseases of the pet rat
- Mycoplasma
- Mammary tumors
- Chronic progressive nephropathy
- Obesity
- Be familiar with the zoonotic diseases associated with rodents
- Understand the major issues involved in keeping wild animals such as prairie dogs, hedgehogs and sugar gliders as pets
1.2. Review and Resources on Laboratory Animal Medicine
Please review relevant material from 1st year Comparative anatomy before attending these lectures. Additional material can be found in
- A Colour Atlas of the Anatomy of Small Laboratory Animals: Rabbit Guinea Pig by Peter Popesko, et al. available in the Wildlife Library (not for circulation).
The ICE First Step Program on Exotic Small Mammal Medicine, developed by Theresa Lightfoot, is a great supplement to this syllabus.
The following material is presented with an emphasis on companion rodents and small mammals. Information on laboratory animal medicine can be obtained from the references listed in the Introduction to Zoological Medicine course and listed below.
An excellent review of the diseases of laboratory animals can be found at: Baker, David G. Natural pathogens of laboratory mice, rats, and rabbits and their effects on research. Clinical Microbiology Reviews, vol. 11 (2), April 1998:231-266.
There is also an on-line book on the IVIS website: Laboratory Animal Medicine and Management edited by J.D. Reuter and M.A.Suckow.
The Webster library also has an excellent CD-ROM on the local network server for your review: ACLAM Lab Animal Medicine and Science Series II.
1.3. 'Pocket Pets?'
A quote from David L. Graham, D.V.M. PhD.
2. Rodents
2.1. Introduction
2.1.1. Taxonomy (abbreviated list)
| Order Rodentia | ||
| Suborder Sciurognathi | Family Sciuridae | squirrels, marmots, chipmunks, gophers, beavers, kangaroo rats, springhaas |
| Family Muridae | rats, mice, hamsters, lemmings, voles | |
| Suborder Hystricognathi | porcupines, cavies (guinea pigs), capybaras, chinchilllas, agoutis | |
Free-ranging rodents are distributed worldwide and act as important members of the foodchain. They also often act as vectors of disease.
 |
Captive rodents seen most often:
- Zoos - capybara, Patagonian cavy, agouti, prairie dogs, kangaroo rat, etc. guinea pigs, pacas (aguoti paca), hutias, tree porcupine, porcupines, woodchucks, naked mole-rats, degus, etc.
- Pets - Norway rats, mice, guinea pigs, chinchillas, hamsters, gerbils, degus, prairie dogs
- Research Laboratory - Norway rat (varieties), mice, guinea pigs, hamsters, etc.
| Critically Endangered RODENTS from IUCN http://www.redlist.org | |||
| Acomys cilicicus | Gerbillus dalloni | Leptomys elegans | Oryzomys gorgasi |
| Allactaga firouz | Gerbillus floweri | Leptomys signatus | Pappogeomys neglectus |
| Namdapha flying squirrel | Gerbillus grobbeni | Macrotarsomys ingens | White-eared pocket mouse |
| Short-tailed chinchilla | Gerbillus hoogstraali | Lesser small-toothed rat | Pacific pocket mouse |
| Mt. Isarog striped rat | Gerbillus lowei | Makalata occasius | Perdido Key beach mouse |
| Crateromys paulus | Gerbillus mauritaniae | Mallomys gunung | Peromyscus pseudocrinitus |
| Crunomys fallax | Gerbillus occiduus | Melomys rubicola | Peromyscus slevini |
| Dendromus vernayi | Gerbillus quadrimaculatus | Meriones chengi | Pogonomelomys bruijni |
| Dicrostonyx vinogradovi | Gerbillus syrticus | Cabrera's hutia | Pseudohydromys murinus |
| Morro Bay kangaroo rat | Heteromys nelsoni | Large-eared hutia | Alice Springs mouse |
| Giant kangaroo rat | Hylopetes winstoni | Dwarf hutia | Pseudomys glaucus |
| Dipodomys insularis | Isolobodon portoricensis | Little earth hutia | Rattus enganus |
| Dipodomys margaritae | MacDonnel range rock-rat | Microtus evoronensis | Rattus montanus |
| Fresno kangaroo rat | Northern Idaho ground squirrel | Microtus mujanensis | Rhagomys rufescens |
| Tipton kangaroo rat | New Mexico least chipmunk | Mus kasaicus | Sicista armenica |
| Gerbillus principulus | Hidden Forest chipmunk | Garrido's hutia | Sigmodontomys aphrastus |
| Eliurus penicillatus | Mount Graham red squirrel | Nectomys parvipes | Tokudaia muenninki |
| Gerbillus bilensis | Cathlamet pocket gopher | Orthogeomys cuniculus | Tylomys bullaris |
| Gerbillus burtoni | Zyzomys palatilis | Oryzomys galapagoensis | Tylomys tumbalensis |
| Gerbillus cosensis | Leimacomys buettneri | - | Typhlomys chapensis |
2.2. General Health Issues
2.2.1. Non-infectious diseases
- Dental ds./malocclusion
- Woodchucks with vascular ds. - arteriosclerosis, aortic rupture, cardiovascular and cerebrovascular disease etc.
- Hypervitaminosis D in captive beaver, woodchucks, pacas and agoutis eating monkey chow
- Urinary tract ds. - calculi, chronic interstitial nephritis, chronic progressive nephrosis (rats), amyloidosis, nephrotic syndrome
- Diabetes in degus, ground squirrels, sand rats, spiny mice, chinese hamsters
2.2.2. Infectious diseases
- Rabies? rare, but possible, woodchuck is most commonly reported
- Hantavirus reservoirs (see below)
- Encephalomyocarditis virus (rat as reservoir?)
- Parvovirus in porcupines
- Squirrel fibromatosis - pox virus in gray squirrels
- Woodchuck hepatitis/hepatocellular carcinoma - seen in captive animals, viral cause
- Leptospirosis reservoirs (cotton rats, coypus, beavers, muskrats, woodchucks, voles, P. cavies, squirrels, deer mice), does not produce disease in the rodent but act as vectors for spread of the organism
- Borreliosis reservoirs (mice)
- Pseudotuberculosis Y. pseudotuberculosis, Y. enterocolitica (chinchillas, agoutis, beavers, lemmings, voles, mice, muskrats, coypus, prairie dogs, ground squirrels)
- Yersinia pestis (prairie dogs)
- Tyzzers ds. occurs in many
- Fungal dermatitis
- Aspergillosis (capybaras)
- Parasites - variety of mites, tick, fleas, lice and fly larvae (myiasis, cuterebra), variety of helminths common, protozoa usually without disease, coccidia most likely to cause disease.
 |
2.2.2.1. FOCUS ON Hantavirus
Bunyavirus >>> Hantaviruses
| Characteristics of some recognized Hantaviruses | |||
| Hantavirus strain | Geographic distribution | Primary wild reseveoir | Primary disease syndrome |
| Hantaan | China, Korea, East Russia | Striped field mouse | Classic disease (below) |
| Rat-borne (Seoul) | Worldwide (incl.US) | Rats | Milder disease |
| Puumala | Europe | Vole, House mouse | Mild nephropathy |
| Sin Nombre | US | Deer mouse | Pulmonary syndrome |
Hantaviruses are an extremely diverse group of viruses which have probably been around for a long time, many as yet undescribed. The primary wild reservoir host is always a rodent species. Hantavirus does not cause disease in the rodent host. Virus is found in rodent kidney and lungs, and the rodent will produce antibodies to the virus. Virus is shed in the saliva, urine and feces. It is transferred horizontally from rodent to rodent. The virus likely occurs in many different rodent species and may be capable of moving from one to another rodent species but each strain seems to prefer a single species host. Hantaviral antigen has also been detected in non-rodent species such as birds of prey, cats, and the desert cottontail associated with the recent "Four Corner's" outbreak. Transmission from the non-rodent hosts is unlikely.
The classical human disease associated with hantavirus infection is a renal and hemorrhagic syndrome first described in the1930's in Korea (especially prominent during the Korean War). The virus was not isolated until 1978. Now recognized all over the globe with hotspots in Scandinavia and northeastern Asia.
Currently 100,000 - 150,000 cases/year recorded in China alone! Likely attributable to rice farming techniques?
2.2.2.1.1. North American forms of the virus
The first Hantavirus identified in the US was the "Prospect Hill" strain found in the meadow voles, Microtus pennsylvanicus in Maryland and the Midwest. No human disease produced.
Human disease first recognized in the US in May, 1993 as the "Four Corner's" strain: this New Mexico disease was seen in previously healthy adults with sudden onset of fever and ARDS. Most patients died quickly with pulmonary edema and respiratory failure. These are atypical symptoms of the other known hanataviruses. PCR testing of patients and local rodents implicated the deer mouse Peromyscus maniculatusas the major vector/reservoir of the Southwestern outbreak. 20-30% of trapped animals proved positive for serology or PCR. Serologic evidence also confirms the virus in the pinon mouse (P.truei), brush mouse (P.boylii), house mouse (Mus musculus), harvest mouse (Reithrodontomys sp.), rock squirrel (Spermophalus vaiegatus), white-throated wood rat (Neotoma albigula), the western chipmunk (Tamias sp.) and others.
By December 1993: 48 confirmed cases of human hantavirus pulmonary syndrome in the US from 14 different states (majority in N. Mexico, Arizona, Colorado and Utah). 60% mortality.
Investigation into previous cases with similar clinical presentation: earliest confirmed in 1975 (N.Mexico)1991, Oregon, Louisiana (slightly different virus from Peromysicus gossypinus, the cotton mouse)
The "Four Corner's" and Louisiana strain are genetically related to the Prospect Hill strain, but are very different from the other strains (indicating that it is not a recent mutation). Three new strains have since been identified in various parts of the US and Canada.
Predisposing factors leading to the "Four Corner's" outbreak: El Nino produced an extremely wet winter - large rodent food supply - large rodent reproductive year. 10-fold increase in rodents from May 1992- May1993.
2.2.2.1.2. Disease in humans
Virus is transmitted to humans through contact (via inhalation) with rodents or rodent excreta - feces and urine. Rodent bites may also result in infection. Human to human transmission has not been documented.
Classic disease (old world) in humans is hemorrhagic fever and renal complications.
Hantavirus pulmonary syndrome: history of contact, several days later development of fever, mylagia, headache, gastrointestinal signs followed by cough, cardiopulmonary dysfunction, respiratory failure and shock. No renal involvement in any of the cases!! Mean time from first symptoms to death 7 days.
Early diagnosis is obviously important for successful treatment. Incubation period for HPS is felt to be from 1-3 weeks. Symptoms including flu-like signs without upper respiratory component but including a GI complication and a typical hematologic profile should alert medical personnel. History of exposure helps. Rapid serology is available (U. of New Mexico) and PCR has been instrumental in confirming cases (Rockefeller University Laboratory Animal Research Center). The CDC has very strict guidelines for diagnosis of potential and confirmed cases.
See their website for more information at: http://www.cdc.gov/ncidod/diseases/hanta/hantvrus.htm
This disease is now being diagnosed on a regular basis in humans in both North and South America. The mortality rate has drastically reduced since wider recognition and early intervention has become possible.
2.3. Guinea Pigs
| Cavia porcellus |  |
The guinea pig is an herbivorous rodent originating in South America. It was domesticated as early as 1000 BC.
Guinea pigs are still raised for food in South America, and used as pets and research animals around the world.
2.3.1. Basic physiologic and anatomic parameters
| LIFE SPAN | 4-6 yrs. |
| HEART RATE | 230 - 380 bpm |
| RESP RATE | 42 - 104/min. |
| RECTAL TEMP. | 98.8 - 103.1 |
| SEXUAL MATURITY | 3 mo.(M), 2 mo.(F) |
Guinea pigs have classic rodent dentition with two upper and lower incisors designed for gnawing and 1 premolar and 3 molar teeth on either side of the maxilla and mandible designed for grinding rough vegetation. All teeth are open rooted. Guinea pigs are monogastric hindgut fermenters as the rabbit.
- Incisors 1/1
- Canines 0/0
- Premolars 1/1
- Molars 3/3
Anatomic and physiologic peculiarities include:
- no tail
- only 2 inguinal nipples
- large adrenal glands
- very large vesicular accessory sex glands in the male
- large open inguinal ring
- Kurloff bodies
- extended gestation period (59-72 days)
- precocial young
- yeast is normal GI flora
 |
2.3.2. Special considerations for husbandry and nutrition
Guinea pigs are easy to care for. They can be kept in open cages since they are poor climbers or jumpers. They are normally kept on pine shavings.The more appealing cedar shavings should never be used for small animal bedding due to the potential hepatotoxicity from the phenol compounds in the shavings. Shavings must be changed frequently since urine buildup may produce ammonia toxicity with resultant increased susceptibility to respiratory infections or contribute to pododermatitis.
Guinea pigs are normally fed a diet including fresh good quality Guinea pig pellets and fresh fruits and vegetables. Course roughage such as hay may predispose the pig to lymphadenitis. Guinea pigs have an absolute dietary vitamin C requirement. Like some other New World species they are unable to make vitamin C. A deficiency will result in scurvy and eventual death from secondary complications.
Clinical signs of scurvy include a poor hair coat, anorexia, gingivitis, generalized pain, arthropathy especially at costochondral junctions, diarrhea, and respiratory infections. Vitamin C is normally added to all good quality guinea pig diets (pellets). Some owners will also supplement their pigs with fresh citrus fruit daily, or give OTC vitamin C supplements. Pelleted diets must be stored adequately (dry and cool, 22C) to preserve the vitamin content. 3 months after the date of manufacture, the vitamin C content cannot be guaranteed. Often times, the date of manufacture and the storage history prior to purchase of the pellets is unknown, allowing for problems to arise. Always supplement with vitamin C for any disease condition. Subclinical deficiency likely contributes to many disease states. Guinea pigs should never be fed rabbit pellets because they do not have vitamin C added.
| Vitamin C Supplementation in the Guinea Pig |
| 200-1000 mg/L in drinking water (fresh daily) |
| 800 mg/kg of pelleted diet (milled) |
| OR |
| 50 mg/guinea pig/day |
2.3.3. Basic diagnostic approaches
- Blood collection in the guinea pig can be performed at various sites including the jugular (difficult), pre-caval, lateral saphenous vein and the cephalic vein.
- Radiographs can be performed with manual restraint or light sedation (see formulary).
- Ketamine and valium work well for sedation.
- Oral examinations (malocclusion) may initially be performed with an ear speculum, but a complete examination must be performed under sedation.
2.3.4. Basic therapeutic approaches
Guinea pigs are even more sensitive and susceptible to antibiotic induced enterotoxemia than rabbits. Great care must be taken to choose appropriate antibiotics and use them only when necessary. The drugs listed as "safe" for rabbits are also safe in the guinea pig. Guinea pigs are often infected with Gram (+ ) infections and selection of antibiotics should take this into account.
Oral medication is commonly prescribed for home use and is easy for the owner to administer (antibiotic precautions hold especially for oral meds). IM, SQ administration is similar to rabbits and other small mammals. IV access is challenging utilizing the saphenous or cephalic sites. IO catheters chould be considered when appropriate.
Injectable vitamin C can be given to guinea pigs in the hospital setting. Vitamin C supplementation is recommended for all disease states to eliminate the possibility of subclinical deficiency.
2.3.5. Common problems/diseases
- Scurvy (see above)
-
Cystic calculi/urolithiasis
- Calcium usually involved
- Surgical removal of urinary calculi not uncommon
- Diabetes - similar to adult onset diabetes in humans
Gastrointestinal disorders
- Molar malocclusion "slobbers"
- Very common in chinchillas and guinea pigs
- Most likely dietary cause, type of roughage being offered
- Clinical signs - anorexia, weight loss, appearing hungry but dropping food, salivation
- Tongue (lower arcade) or cheek (upper arcade) lacerations causing pain
- Requires examination and regular trimming under sedation (see end of chapter for special dental instrument pack) ; use of a dental bur is best method
Molar malocclusion in a guinea pig - Cecal impaction
- Gastrointestinal ileus
- Following fasting or anorexia
- Following GI surgery (terminal?)
- Challenging to return motility
- Cloacal impactions
-
Diarrhea (dietary, parasitic,
bacterial)
- Early dx. and aggressive supportive care needed
- Life threatening enterotoxemia
Reproductive disorders
-
dystocia
- must breed before 7 mos. of age
- pubic symphysis calcifies after this age and large offspring cannot fit
- may present as surgical emergency
- Pregnancy toxemia (relationship to obesity, fatty liver)
- Cystic ovaries
 Inguinal herniation following dystocia in a guinea
pig
|
Dermatitis
- Fungal (ringworm, yeast)
- Trichophyton mentagrophytes
- Microsporum canis
- Mites
- Cheyletiella
- Trixacarus cavaie
- Treat with Ivermectin
- Lice
- Fleas
- Barbering
- Pododermatitis
 |
Viral diseases
- Adenovirus
- Cytomegalovirus (Herpes)
- Lymphocytic choriomeningitis virus (LCM) - Guinea pigs not reported to transmit to people (see other rodents)
- Parainfluenzavirus
Bacterial diseases
- "Lumps" cervical lymphadenopathy (Streptococcus zooepidemicus, Streptobacillus moniliformis)
- Pneumonia and rhinitis (Bordatella bronchiseptica, Streptococcus zooepidemicus, others)
- Conjuncitivitis (above pathogens and Chlamydophila caviae)
- Enterotoxemia
- Tyzzer's disease
- Pododermititis
Parasitic diseases
- Ectoparasites (above)
- Eimeria caviae
- Cryptosporidium wrairi
- Balisascaris procyonis
- Encephalitozoon
Neoplastic diseases
- Benign skin tumors
- Fibrosarcoma
- Lipomas
- Mammary fibroadenoma or adenocarcinoma
- Leukemia/lymphosarcoma
2.3.6. Surgery and Anesthesia
Sedation is often used for restraint or minor procedures in the guinea pig. Injectable anesthetics such as Ketamine, diazepam, xylazine are very effective. Major surgical procedures should be performed under inhalation anesthesia. Intubation is difficult in the guinea pig, except in the hands of experienced personnel. Therefore it is not recommended for the occasional surgery. In general, guinea pigs do very well with mask administration of isoflurane. Procedures such as neutering, caesarian section, tumor removal, etc. are usually safely carried out with mask anesthesia. An intravenous or intraosseous catheter and fluid support is recommended. Catheters can be placed in the saphenous or cephalic veins. Subcuticular closures without external skin sutures are recommended since guinea pigs like to chew their incisions.
 |
Neutering is occasionally performed for birth control reasons. The inguinal ring in the guinea pig is very large. Castration must include closure of the inguinal ring. Dystocias may also involve herniation into the inguinal ring. Caesarian section is probably the most common cause for emergency surgery in the guinea pig.
Gastrointestinal surgery is sometimes required for removal of foreign bodies such as trichobezoars. An enterotomy carries with it a grave prognosis. The gut of the guinea pig does not tolerate much invasion and usually responds with an intractable ileus.
2.4. Chinchillas
2.4.1. Basic physiologic and anatomic parameters
 |
The chinchilla is closely related to the Guinea Pig. They differ in that they are generally smaller in size, have a long furry tail, and live a lot longer. They were bred for their wonderful soft coats for the fur coat industry, but have since become very popular pets. They are currently protected as wild animals in their natural range in the Andes mountains.
| LIFE SPAN | 8-12 yrs. |
| HEART RATE | 180 - 380 bpm |
| RESP RATE | N/A |
| RECTAL TEMP. | 96.8 - 100 |
| SEXUAL MATURITY | 3 mo. |
- Chinchillas have an even longer gestation period than the guinea pig (111-128 days)
- Very precocial young
- They are nocturnal and like to burrow during the day.
- They are very intolerant of hot weather.
2.4.2. Special considerations for husbandry and nutrition
Chinchillas are generally kept caged in a large enclosure in the house. They are very attracted to chewing electric cords and should not be left out unsupervised. They should have a place to burrow or hide in the cage. Unlike the guinea pig, chinchillas can jump and climb fairly well. Chinchillas must have a dust bath, preferably daily. This consists of a bowl with a special mixture of silver sand and Fuller's earth (available at pet stores). The dust bath can be witheld or limited in situations with open wounds or conjunctivitis, etc.
The chinchilla is normally fed chinchilla pellets, hay and a variety of fresh greens, nuts and fruits. They can also be fed rabbit pellets since they do not have a special requirement for Vitamin C. They like raisins and yogurt drops especially and care should be taken not to overdo the treats.
2.4.3. Basic diagnostic approaches
- Venipuncture sites are as in the guinea pig.
- Radiology is also very similar to the guinea pig.
- Normal blood values are listed at the end of this chapter.
 |
2.4.4. Basic therapeutic approaches
Chinchillas also have a very sensitive GI flora and are susceptible to enterotoxemia. They also suffer from Gram (+) infections. The same medications recommended for the rabbit and the guinea pig are recommended for the chinchilla.
2.4.5. Common problems/diseases
 |
- "Slobbers" molar malocclusion (more common than in the guinea pig)
- Heat stroke (optimal ambient temperature 65-80F)
- Electrocution
- Thiamine deficiency (neurologic)
Dermatitis
- Barbering
- Fungal (Trichopyton mentagrophytes), yeast
- Fur mites
- Fur slip
Gastrointestinal disorders
- Intestinal ileus
- Constipation (dehydration)
- Trichobezoar (hairball)
- Intussusception
- Mucoid enteritis, enterotoxemia
- Bacterial enteritis
- Protozoal enteritis (Giardia)
Bacterial disorders
- Pneumonia
- Salmonella enteritis
- Listeria enteritis and encephalitis
- Yersinia pseudotuberculosis (diarrhea, encephalitis)
- Abscesses following fighting
Parasitic disorders
- Ectoparasites (above)
- Giardia
- Cryptosporidia
- Balisascaris procyonis
2.5. Hamsters, Gerbils, Rats and Mice
| Species | Life span | Heart rate | Resp rate | Rectal temp | Sexual maturity | Gestation | Weaning age |
| Hamster | 1.5-2 yrs. | 250-500/min. | 35-135/min. | 98.6- 100.4 | 10 wk (M) 6 wk (F) | 15-16 d. | 20-25 d. |
| Gerbil | 3-4 yrs. | 360/min. | 90/min. | 98.6- 101.3 | 70 d.(M) 65 d. (F) | 27-48 d. | 20-26 d. |
| Rat | 2-3 yrs. | 250-450/min. | 70-115/min. | 96.8- 99.5 | 65 days | 21-23 d. | 21 d. |
| Mouse | 1.5-3 yrs. | 325-780/min. | 60-220/min. | 97.7- 100.4 | 50 days | 19-21 d. | 21-28 d. |
2.5.1. Hamsters
|
 |
Hamsters should be kept alone. Fighting is common. They are nocturnal and will hibernate at temperatures below 5 degrees C. They possess large bilateral flank scent glands that can become impacted. They are used extensively in research due to their immune system peculiarities (cheek pouches).
2.5.1.1. Common problems and diseases
- Ammonia toxicity (poor cage hygiene), and phenol toxicity (cedar shavings)
-
Enterotoxemia :
- most acutely sensitive of the rodents
- Use only SAFE antibiotics as listed for rabbits and guinea pigs
-
Proliferative ileitis "wet tail"
(Lawsonia intracellularis), often with prolapse
- Agressive supportive therapy
- Antibiotics
- Tyzzer's disease (Cl. piliformes)
- Diabetes mellitus (hereditary)
- Renal amyloidosis
- Urolithiasis
- Neoplasia, impaction of the flank glands
- Lymphocytic choriomeningitis virus (LCM)ZOONOTIC mice are natural host
- Tapeworms (hymenolepis nana) ZOONOTIC
- Demodex
- Lymphosarcoma
- Adrenocortical adenomas (Cushings, hairloss) Lysodren therapy
- Malnutrition (low protein) induced hairloss
- Staph pyoderma
2.5.2. Gerbils
Gerbils are generally less aggressive and more compatible then hamsters. They are still best kept alone. They are hardier than hamsters. Gerbils have tails.
2.5.3. Rats
Rattus norvegicus - laboratory rat (albino), hooded rat ("Long Evans stock") ... many strains!!
 |
Rats are a surprisingly good companion animal: intelligent and responsive. However they have a short life span ( 2-3 years). Rats are omnivorous and have a tendancy for obesity. Chromodacryorrhea can be very pronounced in the rat (porphyrins in the urine and other glandular secretions such as tears and nasal discharge).
2.5.3.1. Common problems and diseases
- Mycoplasma - pneumonia, reproductive disease, arthritis, encephalitis
- Tyzzer's disease
- Subcutaneous abscesses
- Staph pyoderma
- Ringworm - trichophyton spp.
- Ammonia toxicity
- Self-mutilation
- Chronic progressive nephropathy (old age disease)
- Obesity
Viral diseases
- Parvovirus
- Sialodacryoadenitis virus (coronavirus) - respiratory
- Sendai virus (PI I virus, more important in mice) - respiratory
- Bunya virus - Hanta virus
Parasitic diseases
- PinwormsSyphacia muris
- Aspicularis teraptera, another oxyurid
- Tapeworms - Taenia taeniaformis (intermediate host for cat)
- Hymenolepis nanaZOONOTIC
- Mites (several species)
- Fleas
 |
Neoplasia
-
Mammary fibroadenoma
- Both males and females
- Grow rapidly!
- Easily resected, but may recur
- Mammary adenocarcinoma
- Squamous cell carcinoma
- Pituitary adenoma
- Uterine, ovarian and vaginal carcinomas
- MANY strain specific tumors
 |
2.5.4. Mice
Mice are rarely seen in small animal practice. They are extensively used in research and well understood from a laboratory animal perspective.
 Scabies in pet mouse
|
2.5.4.1. Common problems and diseases
- Barbering
- Neoplasia (variety)
Bacterial diseases
- Tyzzer's disease (first described in mice!) - death, diarrhea
- Salmonella
- Streptococcus - respiratory
- Mycoplasma - respiratory, encephalitis
Viral diseases
- Mousepox
- Cytomegalovirus (worse for young)
- Lymphocytic choriomeningitis virus (arenavirus) - ZOONOTIC, neurologic, sudden death
- Sendai virus - respiratory
- Pneumonia virus of mice (Paramyxovirus)
- MANY other viruses of importance to lab animal medicine
Parasitic diseases
- Toxoplasmosis (intermediate host)
- Pinworms Syphacia obvelata
- Aspicularis teraptera, another oxyurid
- Tapeworms - Taenia taeniaformis (intermediate host for cat)
- Hymenolepis nanaZOONOTIC
- Mites (several species)
- Ringworm
2.6. Prairie Dogs
2.6.1. Basic data
- Rodents in the Sciuridae family
- Ethical issues surrounding management of wild populations and taking for pets
- Legal in many states to take from wild; large export market to Japan
- Black tailed prairie dog (Cynomys ludovicianus) being considered for protection
- Utah prairie dog (Cynomys parvidens) listed as threatened
- Mexican prairie dog (Cynomys mexicanus) listed as endangered
- Dangers of Yersinia pestis
2.6.2. Care and husbandry tips
- Do not keep in wire cages - dental injuries
- Main diet of rodent block, grass hay
- AVOID dog food or monkey chow, excessive Vitamin D
2.6.3. Health issues
- Ectoparasites, fleas
- Ringworm
- Pasteurella abscesses
- Pododermatitis
- Yersinia pestis plague, high mortality, ZOONOTIC
- Other zoonoses: Tuleremia, Monkey Pox
- Dental disease
- Obesity
- Respiratory problems due to pasteurella, pulmonary mites, dental disease
- Baylisascaris
- Antibiotic choices as for rabbits and guinea pigs
For more information on prairie dogs see references
2.7. Tables of Normal Values for Various Rodent Species
2.7.1. COMPLETE BLOOD COUNT
| Red blood cells | Guinea pig | Chinchilla | Hamsters | Gerbil | Rat | Mouse |
| PCV (%) | 35 - 50 | 25 - 54 | 40 - 52 | 35 - 45 | 40 - 50 | 35 - 50 |
| RBC (106/μl) | 4.5 - 7.0 | 5.2 - 10.3 | 4 - 9.3 | 8.3 - 9.3 | 7.2 - 9.6 | 9.3 - 10.5 |
| Hb (g/dl) | 11 - 15 | 8.0 - 15.4 | 9.7 - 16.8 | 10 - 16 | 14.8 | 12 - 14.9 |
| MCV (fl) | 81 | 32.1 - 69.2 | - | - | - | - |
| MCHC (%) | 30 | 20 - 38.5 | - | - | - | - |
| MCH (pg) | 25 | 10.4 - 19.8 | - | - | - | - |
| White blood cells | - | - | - | - | - | - |
| WBC (103/μl) | 5 - 12 | 1.6 - 45.1 | 7 - 15 | 9 - 14 | 8 - 14 | 8 - 14 |
| Neutrophil (%) | 28 - 34 | 1 - 78 | 16 - 28 | 10 - 20 | 30 | 26 |
| Lymphocyte (%) | 39 - 72 | 19 - 98 | 64 - 78 | 70 - 89 | 65 - 77 | 55 - 80 |
| Monocyte (%) | 3 - 12 | 0 - 5 | 2 | 0 | 4 | 5 |
| Eosinophil (%) | 1 - 5 | 0 - 9 | 1 | 1 | 1 | 3 |
| Basophil (%) | 0 - 3 | 0 - 11 | 0 | 0 | 0 | 0 |
2.7.2. SERUM BIOCHEMISTRY
| Chemistry compound | Guinea pig | Chinchilla | Hamster | Gerbil | Rat | Mouse |
| ALT (U/l) | 10 - 25 | - | 22 - 122 | - | People who viewed this content, also viewed...
 Tufts OCW material is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License. Legal NoticesPrivacy |