The Gentle Gerbil

By Robert J. Russell and Jim A. Stunkard.

Pet gerbils usually belong to the species commonly known as Mongolian gerbils (Meriones unguiculatus). They are very inquisitive, clean, gentle animals and much less aggressive than other rodents. They are native to desert regions of northeastern China and eastern Mongolia.

The most common color is a mixed brown, but black and white mutations also occur. Because of the lack of variety in their coat colors, little interest has been shown by breed fanciers.

Gerbils are naturally desert animals, and they excrete very little urine, therefore producing only a slight odor. They are monogamous (usually one mate for life), and mature animals generally will not accept another mate. The male and female are best paired at 9 to 10 weeks of age prior to sexual maturity to insure successful mating. Gerbils practice coprophagy (as do rabbits; see previous chapter) and obtain B vitamins and probably other nutrients in this manner.

Gerbils have a hairless sebaceous gland, approximately 1/2" in diameter, located in the skin of the abdominal midline. The gland is used for territorial marking and should not be considered abnormal.

Gerbils are not naturally found wild in the United States, and there is concern that they might establish themselves and become pests. It is illegal to maintain gerbils as pets in some States California, for example.

Cages

A variety of plastic and metal solid-bottom shoe box cages are available commercially. Glass fish tanks with tightly fitting covers that provide adequate ventilation are also acceptable. Wire bar cages and exercise wheels often are the cause of broken legs, and their combined use should be avoided.

Enough bedding (1" deep) to permit nest building should be provided; wood shavings, wood chips, ground corncobs, and shredded paper are all acceptable. Provide an enclosed space within the cage as a hiding space.

A breeding pair can be maintained in a cage providing 200 square inches (10" x 20") of floor space and a minimum height of 6".

Dietary Guide

Standard, commercially available, pelleted rodent diets generally are adequate. However, many people supplement these diets with mixed grains and seeds (corn, oats, wheat, barley, sunflower seeds) and vegetables (cabbage, lettuce, carrots). If you do not use a pelleted ration, be sure to feed a mixed ration, as the use of only one seed for example, sunflower seeds can result in nutritional deficiencies.

Although gerbils have a low water requirement, they should be provided with a continuous supply of fresh, clean water. The animals can be maintained at temperatures between 65 and 85 F. Cages usually require changing only every 2 weeks.

Diseases

Generally, gerbils are afflicted by few spontaneous diseases.

Often seen is a condition commonly called red nose, causing hair loss and red, swollen areas of the skin of the nose and muzzle. Staphylococcus generally is the cause. But other bacterial organisms, trauma due to burrowing, or as yet undetermined factors may be involved.

Animals generally recover spontaneously. Sometimes removal of metal feeders and other objects from the cage, and the use of local and systemic antibiotics, are required.

Bite wounds, especially on the tail and tailhead, occasionally occur, and animals may require separation.

Gerbils usually are not affected by external parasites except for the microscopic mite Demodex. Lesions due to its presence are rare.

High death rates can result from the bacterium Bacillus piliformis, the cause of Tyzzer's disease. Affected animals have rough hair coats, become lethargic, go off feed, and suffer weight loss. Diarrhea does not usually occur. Lesions are found in the liver and the intestinal tract.

There is no specific treatment, although antibiotics can produce limited success. Control of stress may be beneficial in prevention.

Incisors

As in other rodents, overgrowth of incisor teeth can occur and trimming may be needed.

Gerbils are rarely infested with intestinal parasites. Pinworms (Syphacia obvelata) and tapeworms (Hymenolopis diminuta) can occur, but clinical signs usually are not seen.

About 20 percent of gerbils develop recurring bouts of spontaneous, convulsive seizures. The seizures commonly are of short duration and usually seen after handling. Treatment generally is not necessary.

The antibiotic streptomycin should not be used in gerbils, as it has been associated with high death rates.

Robert J. Russell is Director, Laboratory Animal Sciences Program, Program Resources Inc., Frederick, Md. Jim A. Stunkard is Director of the Bowie Animal Hospital, Bowie, Md.