II. Nutritional Problems
III. Neoplasia
IV. Geriatric Diseases
V. Starvation and Water Deprivation
VI. Tail Lesions
VII. Malocclusion
VIII. Rough Hair Coat
IX. Aminoglycoside Toxicity
The gerbil displays spontaneous epileptiform seizures (see photo).
These seizures may be precipitated by sudden stress, handling, or introduction
to a novel environment. Incidence of this syndrome is about 20% in
natural populations. The condition appears to be inherited, and both
seizure-resistant and seizure-sensitive strains have been developed by
selective breeding. Inbred animals can have up to 100% incidence.
Seizures vary in severity from mild hypnotic episodes characterized by
cessation of activity and twitching of the pinnae and vibrissae, to severe
myoclonic convulsions followed by tonic extensor rigidity. Post-seizure
fatality occurs in less than 1% of affected animals. There is no
permanent damage. Seizure onset occurs at 2 to 3 months of age with
seizure incidence and severity increasing with age until the animal reaches
six months of age. A refractory period of up to five days can follow
more severe seizures. Research has shown that the seizure response
can be almost completely suppressed in genetically predisposed animals
if they are frequently stimulated by handling during the first three weeks
of life. Anticonvulsant therapy is neither necessary nor recommended. 
Gerbils normally thrive on a good quality rodent chow, but may have
deficiency problems when fed home-made diets, sunflower seed diets, or
table scraps which lack specific nutrients. Signs of deficiencies
will be manifest as in other mammals. A feeding level of 5 grams
of pelleted chow per day has been recommended to prevent obesity which
can predispose to islet cell hyperplasia and hyperglycemia. 
III. Neoplasia
Older gerbils commonly develop a number of spontaneous neoplasms most commonly affecting the skin, adrenal gland, kidney, spleen, intestine and the female reproductive tract. The most frequently seen neoplasms include leiomyomas, subcutaneous fibrosarcomas, sebaceous gland adenomas and adenocarcinomas, splenic hemangiomas, adrenal adenomas, duodenal adenocarcinomas (usually in males), and malignant melanomas. Diagnosis is based upon clinical course of the disease and histopathology.
Syndromes commonly seen in aged gerbils include cystic ovaries (50% of all females) and chronic interstitial glomerulonephritis. Cystic ovarian disease accounts for the majority of cases of decreased fertility in breeding aged gerbils. Gerbils with glomerulonephritis develop polyuria and polydipsia, and progressive weight loss clinically. Chronic interstitial glomerulonephritis may occur in combination with neoplastic lesions.
V. Starvation and Water Deprivation
These managerial problems are often seen with overcrowding or prolonged shipping. Weanlings are particularly susceptible to starvation and water deprivation if they are unable to reach the food hopper or sipper tube on the water bottle. A good history and review of husbandry practices help in formulating a diagnosis since no gross lesions except an empty stomach and loss of body fat (adult gerbils only) are observed on post-mortem exam. Attention to proper husbandry practices is the main aim in prevention.
Barbering of the tail hairs is observed in cages that are overcrowded.
The hair grows back once the cage population is diminished. Fractures
of the tail vertebrae, and slipping of the tail skin can all occur with
improper handling (A.). This usually involves picking up animals
by the distal portion of the tail. Surgical amputation with cautery
(silver nitrate cautery shown in B.) supportive post-surgical care may
be necessary when large amounts of tissue are compromised. Such injuries
may be prevented by handling animals by the base of the tail.
Although much less common than in other rodent species, malocclusion and overgrowth of the incisors do occur in gerbils. Gnawing on metal in the cage can cause the incisors to break resulting in overgrowth of the opposing pair. Clinical signs of malocclusion can include weight loss, depression and emaciation. Treatment is by carefully trimming back the overgrown teeth with Dremmel tools. Resco nail clippers may also be used but it is possible to case detrimental longitudinal fractures of the teeth with this method.
An unkept, matted hair coat is often an indicator of excessive humidity levels in the environment (50% relative humidity). (Rough looking hair is also the most frequent physical reflection of active disease in most rodents.) This problem is often seen in animals kept in solid-topped aquariums or microisolator cages. Adequate air exchange to remove excess moisture is the best preventative measure.
Aminoglycosides are toxic to gerbils. Antibiotic ointments containing
aminoglycosides have caused mortality presumably from ingestng the ointment,
and experiencing neuromuscular paralysis from impaired acetylcholine release.
Back to Disease Categories