Gerbils have few spontaneous illnesses. A proper and consistent diet, clean cage and bedding, and appropriate housing all contribute to maintaining good health.
Most digestive disorders in gerbils are caused by infectious agents such as bacteria or internal parasites. Diarrhea is a common sign of many gastrointestinal diseases.
Malnutrition may also occur if gerbils are not fed a diet specifically formulated to meet their dietary needs.
Tyzzer's disease, caused by Clostridium piliforme bacteria, is the most common infectious disease in gerbils. The bacteria are more likely to infect young or stressed gerbils. Signs of infection include depression, rough hair coat, hunched posture, loss of appetite, dehydration, and watery diarrhea. Because this disease is contagious, a sick gerbil should be separated from other gerbils. The bacteria are transmitted by contaminated feces, so the infected gerbil's cage must be thoroughly cleaned and disinfected. Sick gerbils should be handled after other gerbils, and you should always wash your hands thoroughly in between handling each gerbil.
Gerbils can be infected with several strains of Salmonella bacteria. Signs of infection include diarrhea, dehydration, weight loss, rough hair coat, a swollen or bloated abdomen, or fetal death in a pregnant female. Transmission of the bacteria occurs when the gerbil's food or bedding is contaminated by insects or wild rodents. Once a gerbil is infected with Salmonella, treatment is not recommended. The infected gerbil should be isolated and its environment should be thoroughly sanitized and disinfected. Salmonella infections can be transmitted to humans, even if the infected gerbil does not seem sick.
Gerbils can be infected with these intestinal parasites by exposure to another infected gerbil's feces. However, there may be no obvious signs. A veterinarian can diagnose pinworms by examining your gerbil or testing its feces. Several types of medication, which often must be mixed with the gerbil's feed or water, may be prescribed for treatment. The infected gerbil's cage should be thoroughly cleaned and disinfected because the worm's eggs may still be present.
Gerbils can be infected with 2 kinds of tapeworms, Rodentolepis nana (dwarf tapeworm) and Hymenolepis diminuta. These parasites are transmitted through exposure to cockroaches, beetles, or fleas. The dwarf tapeworm can also infect humans. Gerbils usually do not have signs of tapeworms, but heavy infections can cause dehydration or diarrhea. A veterinarian can diagnose tapeworm infection with tests on your gerbil or its feces, and prescribe appropriate treatment. The cage of the infected gerbil should be thoroughly cleaned and sanitized, and whatever may have transmitted the infection (cockroaches, for example) should be eliminated.
Bone and Muscle Disorders
Broken bones may occur if a gerbil's leg or foot becomes stuck or trapped—for example, in a wire exercise wheel or in mesh flooring. The gerbil's delicate tail may also be injured in this way. Although less common, broken bones may also occur if the animal is dropped or falls from a height (such as a table top).
Disorders of the skin are relatively common in pet rodents, including hair loss and infestation with various parasites of the skin. There are several disorders that are specific to gerbils; however. These include porphyrin deposits around the nose and eyes, and a condition known as tail-slip.
Irritation of the Face and Nose
Environmental stressors, such as incompatible cage mates, high humidity, and overcrowding, can cause gerbils' tear glands to secrete an excess of porphyrin, a protein, around the nostrils and eyes. Accumulation of this reddish-brown porphyrin can cause skin irritation, which leads the gerbil to scratch and hurt itself. It can also lead to hair loss, skin redness, scabbing, and sores. These sores, in turn, can become infected, and the infection can spread. They are itchy, and if the gerbils scratch, the sores will bleed. Sometimes these sores heal by themselves, but more often the infection gets worse. Your veterinarian can diagnose these infections. Treatment includes careful cleaning of the affected area, and application of a prescribed antibiotic ointment. To prevent this condition, monitor the temperature (60 to 70°F) and humidity (below 50%) of your gerbil's environment, and separate any animals that are incompatible.
Hair Loss and Tail-slip
Gerbils may lose patches of hair on the face and around the tail and hindquarters. Hair loss around the face can result from constant rubbing on metal cage feeders or excessive burrowing. Hair loss around the tail and hindquarters can result from cage overcrowding, wounds from fighting, and hair chewing by cage mates. This can be prevented by fixing these environmental conditions and separating the animals that may be fighting.
Picking up a gerbil by the tail can result in fur loss or cause the skin on the tail to slip off. This is called tail-slip. The portions of the tail that are exposed by skin slippage often rot, and they must be treated by amputation. This problem can be prevented by never picking a gerbil up by the tail.
Rough Hair Coat
When humidity levels are too high, gerbils may develop rough and matted hair coats. This often occurs in gerbils that are kept in tanks without adequate ventilation. Be sure that the cage is adequately ventilated and that the humidity level in the home is kept under 50%.
Gerbils can occasionally become infected with mites. Old age and infirmity can make a gerbil more susceptible to infection. Although mites are hard to see with the naked eye, gerbils may show other signs such as fur loss and dry, scaly, irritated skin on the back and rump. A veterinarian can prescribe medication for treatment. Bedding should be changed frequently and the cage sanitized and disinfected.
In older gerbils, the ventral marking gland on the abdomen (see Gerbils: Description and Physical Characteristics of Gerbils) is at risk for developing tumors, some of which may be benign. The affected gland may develop open sores and become infected, but the tumors rarely spread. Other skin tumors may affect the ears or feet. Masses may be surgically removed. The outlook for a gerbil with a tumor varies with the size, stage, and timing of the removal. Prompt treatment by a veterinarian improves the chances of successful treatment.
Gerbils may spontaneously develop seizures. These may be inherited, or they may be caused by sudden stress, improper handling, or introduction to a new environment. Seizures occur in about 20% of gerbils, but they are uncommon in many pet strains. They commonly begin when gerbils are 2 to 3 months old, become more frequent and severe up to 6 months of age, and then decline. Seizures last several minutes and can range from mildly trance-like behavior with twitching ears and whiskers to severe muscle convulsions and stiffness. Death from seizures is rare and there is no permanent damage. No medication is necessary. Seizures can be prevented or reduced in gerbils that are genetically predisposed if the gerbils are handled frequently during the first 3 weeks of life.
Gerbils that are more than 1 year old often develop an inflammation of the tiny blood vessels in the kidneys, a condition known as glomerulonephritis. Signs include excessive urination and thirst and weight loss. Supportive care with fluids may be required. Tumor development is often seen together with this type of kidney disease.
Masses in the Inner Ear
About half of gerbils greater than 2 years old develop masses in the inner ear. These masses—called aural cholesteatomas—push the eardrum far into the ear, causing permanent damage to the inner ear. Affected gerbils may tilt their head to one side.
Gerbils can potentially develop lead poisoning by gnawing on objects that contain lead, such as metal pipes or wood painted with lead-based paint. Gerbils more than 10 months old can develop deposits of a certain kind of protein, called amyloid, in the spleen, liver, lymph nodes, pancreas, hormone glands, heart, and intestines. Signs of amyloid deposits include loss of appetite, dehydration, weight loss, and death.
Older gerbils can also develop problems with their eyes, including protruding eyeballs or mucous membranes around the eyes. Eye injuries may result when incompatible gerbils fight.
Last full review/revision July 2011 by Katherine E. Quesenberry, DVM, MPH, DABVP (Avian); Kenneth R. Boschert, DVM, DACLAM