Clinical pathology and sample collection of exotic small mammals.

The clinical pathology of some of the less common and newly emerging small mammal species is detailed in this article. The species covered here include the chinchilla, prairie dog, African hedgehog, and sugar glider. Venipuncture sites and sampling techniques are discussed in general and for each species. Detailed information on the hematology and serum biochemistry values of these animals is presented in numerous tables. Specific information is also provided for urinalysis, fecal analysis, dermatologic sampling, and cytology.     

Skin disorders of small mammals

Small mammals are frequently presented to the veterinary surgeon for skin disorders as children's pets, laboratory animals or commercial breeding groups. The role of the veterinary surgeon in these different categories is examined. Investigation and management of these disorders is discussed placing particular emphasis on a diagnostic approach and highlighting those areas which differ from canine and feline dermatology. Common dermatoses of these animals are described on an aetiological basis.     

Oral disorders of exotic rodents.

Our dental knowledge of rodents is still patchy but their increasing popularity and advances in technology allow us to make good strides toward better understanding. Cutting incisors with nail clippers and treating incisor problems without examining cheek teeth is no longer acceptable. Good practice dictates that a thorough examination is performed, a diagnosis is made, and treatment is planned and executed appropriately. Dentistry is expanding at a tremendous rate; the next few years should provide plenty of opportunities to solve most of the remaining problems with dental disease in rodents.     

Yersiniosis in captive exotic mammals.

Within a 2 1/2-month period, Yersinia pseudotuberculosis infection occurred in 3 blesbok (Damaliscus dorcas), 1 dik-dik (Madoqua kirkii), and 1 giant anteater (Myrmecophaga tridactyla) at the National Zoological Park, Washington, DC. Lesions consisted of fibrinonecrotic enteritis and peritonitis, mesenteric lymphadenitis, and embolic pyogranulomatous lesions in the liver, spleen, and lungs. Feed contaminated with the feces of wild rats and pigeons was thought to be the source of infection.     

Fungal diseases in small mammals: therapeutic trends and zoonotic considerations.

As medical knowledge continues to expand, the division between animal and human diseases continues to decrease. The popularity of small mammals in lieu of the increased numbers of immunocompromised individuals will require increasingly broader understandings of zoonotic disease. The vast amount of animal research in areas of human disease requires diligent study to stay abreast of emerging diagnostics and therapeutics. The core requirements of skin scrapings, fungal culture, and microscopy for the diagnosis of small mammal fungal disease, however, are unchanged.     

Endocrine diseases of rodents.

The frequency of documented endocrine diseases in rodents and other small mammals varies considerably among the species maintained as pets, biomedical research animals, or display animals in zoos. The clinical diagnosis of endocrine diseases almost never occurs in free-ranging animals in their native habitat. Feral animals that have clinical endocrine disease, such as neoplasia, adrenal cortical hyperplasia, or diabetes, would exhibit clinical signs of altered behavior that would result in their removal by predators. The diagnosis of endocrine disease thus takes place in the relatively protective environment of captivity. This observation should forewarn pet owners and clinicians caring for these animals that the environment contributes to the development of endocrine diseases in these animals.     

Respiratory diseases of rodents.

Practitioners may be called on to treat rodents with respiratory diseases or to advise clients concerning the care of these rodents. Respiratory diseases of mice, rats, guinea pigs, and Syrian hamsters are well known because of the use of these species in research, whereas few or no reports of respiratory disease in rodents of other species exist. Features of the respiratory diseases of these four commonly encountered species are reviewed, including causes; clinical signs; diagnostic procedures; preventive measures; and, where appropriate, therapies.     

Analgesia of small mammals.

Small mammals receive analgesics much less frequently than more familiar species such as dogs and cats. This is probably related to the greater difficulty of recognizing pain in these species, and the uncertainty as to the most appropriate analgesic regimen to implement when the presence of pain is suspected. However, the same principles of pain assessment and analgesic use that are applied when dealing with other companion animals can be used to manage pain effectively in small mammals. All of the commonly used analgesic agents can be used safely and effectively in small mammals, although the size of many of these animals limits the use of techniques such as epidural administration or transdermal drug delivery systems. As with other species, it is important to integrate an analgesic regimen with the overall scheme of perioperative care, and to try to implement preemptive and multi-modal analgesic therapy.     

Fungal diseases of laboratory rodents.

Although fungal disease is uncommon in rodents, dermatophytosis is the most common mycosis seen in clinical practice. T. mentagrophytes is the most common etiologic agent, and the guinea pig is the most common species affected, although there are reports in all pet and laboratory rodent species except the gerbil. Despite the low incidence of clinical disease, rodents are common asymptomatic carriers of dermatophytes, and ringworm is the most common zoonotic disease transmitted from rodents to people.     

Spontaneous tumors of small mammals.

The most common tumor of guinea pigs is bronchogenic papillary adenoma; of hedgehogs is mammary gland adenocarcinoma; of hamsters is adrenal cortical adenoma; of gerbils is ovarian granulosa cell and theca cell tumors; of mice is pulmonary carcinoma; and of rats is mammary fibroadenoma. A relatively low incidence of tumors is described for chinchillas and hamsters, whereas the incidence of tumors is high for gerbils, hedgehogs, mice, and rats. Limited literature regarding neoplasia exists for prairie dogs, sugar gliders, and chinchillas.     

Skin diseases of ferrets.

This article describes the most common diseases that affect the integumentary system of ferrets. Emphasis is placed on diagnosis and treatment of each disease.     

Viruses and virus diseases of marine mammals.

Poxvirus and several serotypes of calicivirus cause recognizable disease in marine mammals. Pox lesions in pinnipeds are raised and proliferative and are seen most frequently after confinement in captivity. In cetaceans, a poxvirus is associated with a much more benign and chronic lesion called a "tattoo." Numerous caliciviruses of differing antigenic types have been isolated from vesicular lesions and aborted fetuses of northern fur seals and California sea lions as well as from clinically normal and orphaned northern elephant seal pups. An adenovirus has been isolated from a sei whale and an enterovirus has been isolated from a gray whale.     

Nonreproductive surgery in small mammals.

The sophistication of soft-tissue surgery techniques in small mammals is increasing rapidly. Exotic animal practitioners must be familiar with the diseases, conditions, and anatomic variations of each small-mammal species. The small size of these patients should not preclude the use of technologic advances available for other small animals. Despite these challenges, successful resolution of surgical problems in small exotic mammals is not only possible but also should be the expected result of veterinarians' efforts in such cases.     

Anesthesia and analgesia for small mammals and birds.

This article should help the veterinarian to assess pain in small mammals and birds. The focus is on a multimodal approach to anesthesia and analgesia using opioids, nonsteroidal anti-inflammatory drugs, alpha(2)-agonists, dissociatives, and local anesthetics as injectables, constant rate infusions, local blocks, and epidurals. Drugs used for induction, intubation techniques, and inhalant anesthesia are discussed. Protocols for critical patients and doses of common analgesics are covered.     

Surgical sterilization in small mammals. Spay and castration.

The intrinsic physiologic and anatomic differences between small exotic mammals and the species that are more familiar to veterinary practitioners (i.e., dogs and cats) are substantial. This discussion is limited to rabbits, mice and rats (murid rodents), hamsters and gerbils (cricetid rodents), and guinea pigs and chinchillas (hystricomorph rodents). In addition to their anatomic and physiologic differences, differences in behaviors, such as their reaction to stress and pain, exist. Preoperative and postoperative care, basic surgical techniques unique to these species, and useful materials are discussed.