Tularemia (Rabbit Fever) in Cats

Wild rat by some water

Tularemia is a rare but potentially fatal disease that occurs in wild and domestic animals. Rabbits and wild rodents are the primary species affected (hence the nickname) but other species, including humans, can also contract the disease.

Dogs do become infected with the causative organism, but it appears that resulting illness, if it occurs, is symptomless or mild. On the other hand, domestic cats are very susceptible to tularemia and have been known to transmit the bacteria to humans. It’s also important to note that cats don’t need to be clinically sick in order to transmit the disease.

What causes tularemia?
Tularemia is caused by a bacterium — Francisella tularensis — that’s present all over the world. In the United States, cases of tularemia have been reported in all states except Hawaii. According to the Centers for Disease Control, in 2012, most of the human cases reported were in Oklahoma, Missouri, Kansas, and Arkansas. The bacteria is highly infectious — entering the body via skin, eyes, mouth, throat or lungs; by ingestion, inhalation and even by drinking contaminated water.

How would your cat get tularemia?
According to the Center for Food Security & Public Health, the bacterium that causes tularemia can be found in the organs or body fluids of infected animals. Once in the environment, the organisms can survive for long periods of time (weeks to months) in the soil, vegetation or water and then serve as a source of infection for other animals or humans. Animals typically get tularemia by ingesting contaminated food (raw meat from infected animals) or by drinking contaminated water. They can also inhale the aerosolized bacteria, have it enter their bodies through mucus membranes or breaks/cuts in skin, or become infected by biting flies or ticks.

What are the symptoms of tularemia in cats?
As is the case with other susceptible species, the signs of a tularemia infection can vary remarkably; they range from no signs at all, to mild fever and enlarged lymph nodes (lymphadenopathy) to death. When they’re sick, cats may also be anorexic, dehydrated, or listless with ulcers, abscesses, jaundice, pneumonia and/or enlargement of their livers or spleens.

How is tularemia diagnosed and treated?
If your veterinarian is suspicious that your cat might have tularemia, she’ll want to run special serologic blood tests looking for antibodies against the bacteria. Unfortunately, because it takes time for your cat’s immune system to mount a detectable response, these tests may not be diagnostic during the first few weeks of illness. A definitive diagnosis can also be made if the organism can be cultured from tissue specimens on special culture media.

Once infection with tularemia is diagnosed or suspected, antibiotics are usually effective in treating the illness — especially when given early in the disease. Recovery from the infection does produce long-lasting immunity.

According to MERCK, efforts are underway to develop safe and effective vaccines for pets and people.

What can you do to prevent tularemia infection?
The only way to completely protect your cat from infection is to keep him free of ticks and other biting insects. Also, keep him indoors away from the opportunity to hunt or to encounter the organism in the environment. It’s important, however, to remember that you are also at risk. The most common source of infection for people is the bite of an infected tick so take care when gardening, clearing weeds/brush or even mowing lawns.

If you have any questions or concerns, you should always visit or call your veterinarian -- they are your best resource to ensure the health and well-being of your pets.

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Reviewed on: 
Thursday, June 5, 2014