Diseases in Rodents

What are some of the common diseases of pet rodents?

Common conditions of pet rodents include respiratory diseases, gastrointestinal problems, dental problems, and tumors.


What are the signs of respiratory infections?

Signs include nasal and/or ocular (eye) discharge in mild infections, and wheezing, coughing, and open-mouth breathing in severe infections (pneumonia). Animals with pneumonia often stop eating and become lethargic. Bordetella is a type of bacteria that causes respiratory infections in guinea pigs and can prove fatal if not treated promptly. Since rabbits carry this organism without showing signs of illness, rabbits and guinea pigs should not be housed together. In mice and rats, respiratory problems are often caused by a type of bacteria called Mycoplasma which can cause many respiratory signs and often leads to chronic respiratory disease. Other infectious agents, such as Pasteurella and Streptococcus bacteria, can also cause pneumonia.

"Several factors irritate the respiratory tract and predispose the pet rodent to a respiratory infection, including dusty cage litter, aromatic cedar chips, and high levels of ammonia from urine accumulation in dirty litter or a dirty cage."

Regardless of the exact cause of respiratory disease in pet rodents, respiratory infections are relatively common. Several factors including dusty cage litter, aromatic cedar chip bedding, and high levels of ammonia from urine accumulation in dirty litter or a dirty cage may irritate the respiratory tract and predispose a pet rodent to a respiratory infection. These factors should be corrected to lessen the incidence of respiratory problems.


What gastrointestinal diseases do pet rodents get?

Gastrointestinal (GI) disease, including diarrhea (commonly referred to in small rodents as 'wet tail') from various causes (such as bacterial or parasite infections) and gastrointestinal stasis (a slowing down of food through the GI tract from changes in the normal GI bacteria), is common in pet rodents. Rodents with GI disease also may have decreased appetites and lethargy. As with other exotic pets, the sooner a rodent showing these signs is seen and treated by a veterinarian familiar with rodents, the sooner the cause of illness may be determined and treated, and the better the prognosis (chance of cure).


Can rodents have dental problems?

All rodents have teeth that grow continuously throughout their lives. Occasionally, these teeth grow too long and cut into the gums, causing pain, or prevent the mouth from closing properly, which often makes the pet stop eating. Sometimes pets with overgrown teeth will drool or have a constantly wet chin (slobbers). The front teeth or incisors are most frequently the problem in small rodents, such as rats and mice, and their excessive length interferes with eating and grooming. Sometimes, guinea pigs and chinchillas have overgrown molars or back teeth, which makes eating challenging or even painful. Chinchillas’ teeth often become impacted underneath their gums at the roots, like impacted wisdom teeth in people, which makes eating extremely painful.


Do rodents get cancer?

Just as in people, cancer is seen in pet rodents. Mammary (breast) tumors are one of the most common types of cancer, especially in rats and mice. Amazingly, breast tissue in these pets covers most of the underside of the body, so breast cancer can appear anywhere from the neck to the groin. Mammary tumors can grow rapidly and have to be removed surgically. Fortunately, many mammary tumors are benign, and the prognosis after surgery is good. Rodents can get many other types of tumors, including hair follicle tumors in guinea pigs and skin tumors in all rodent species.


How are rodent diseases treated?

Respiratory diseases are typically diagnosed based on clinical signs. X-rays can be taken to confirm a diagnosis. With infectious diseases medications, including antibiotics and anti-inflammatory drugs, are generally prescribed. Supportive care in the hospital, including syringe-feeding and fluid therapy, as well as oxygen therapy, may be needed for pets with serious infections such as pneumonia.

Rodents with signs of gastrointestinal disease require-X-rays, blood tests, cultures, or other tests to help determine a diagnosis. Pets that are dehydrated from diarrhea or decreased appetite are typically given fluids and are syringe fed. These pets are treated with appropriate medications, such as antibiotics and anti-parasitic drugs, depending on the cause of their signs. Mildly affected pets may be treated at home, while more severely affected pets may be admitted to the hospital for therapy.

Regardless of the signs of disease in your pet rodent, pet store antibiotics are generally ineffective and should NEVER be used. Sick rodents should be examined by a veterinarian knowledgeable about rodent diseases and administered appropriate treatment under the veterinarian’s care.

"Pet store antibiotics are generally ineffective against diseases of pocket pets and should NEVER be used."

Overgrown teeth need to be trimmed. Trimming the incisors is often done under anesthesia with a drill. In the past, nail clippers or wire cutters were used to trim teeth without anesthesia, but often these techniques resulted in broken teeth, leading to more problems. The diagnosis of overgrown molars (back teeth) usually requires a thorough oral examination under anesthesia and X-rays. Treatment typically involves the use of special dental instruments to file down the molars with the pet under anesthesia. Dental disease can often be prevented in rodents by maintaining them on a proper diet and offering them safe objects on which to chew, such as blocks of wood.

Tumors are removed surgically under anesthesia and tested to determine their cause. Intra-abdominal tumors can often be removed, but the procedure is more invasive and challenging than for removal of external tumors. The smaller the tumor and the earlier it is removed, generally the easier the surgery.


How can I tell if my pet rodent is sick?

Most rodents are prey species that naturally hide their signs until they are very ill. In addition, while some signs of disease in rodents are specific for a certain disease, most are vague and non-specific, such as a rodent with a decreased appetite and lethargy. These signs can be seen with many diseases including pneumonia, cancer, and even kidney or liver failure. ANY change from normal is a cause for concern and an indication that your rodent requires immediate evaluation by your veterinarian.

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