Vet Tells Cat Owners to Watch for Tularemia During the Summer

Tularemia, which also can be a problem in spring and fall, is zoonotic, so it can be transmitted to people through bodily fluids or bites, said Brad DeBey, associate professor of pathology in K-State's Veterinary Diagnostic Laboratory.

Cats typically acquire tularemia by eating infected rabbits or from bites by ticks that have ingested blood from an infected rabbit, DeBey said.

“Most cases I know of where it has been transmitted to humans have been through a bite wound,” DeBey said. “If a sick cat doesn't feel well and bites someone trying to help it, it can be bad because the cat has the organism in its mouth, which makes it easy to spread.”

The K-State lab team diagnoses 20 to 40 cases of tularemia per year, with more than 90 percent of the diagnoses in cats. However, primates have been diagnosed as well, DeBey said. Dogs and sheep also can be susceptible to the disease, although it is rare in those species.

DeBey said most cases he's observed are from eastern Kansas. A recent case was from south-central Nebraska.

“My feeling is that while eastern Kansas does have many positive cases of tularemia, there are probably a lot more cats that die from tularemia because they weren't diagnosed with it,” he said.

Clinical signs in cats with tularemia include lethargy, anorexia and fever. It also is possible for a clinically healthy cat to transmit the disease if the organism is present in its mouth, even if the cat hasn’t yet developed symptoms, DeBey said.

The incubation period for tularemia is relatively short. Owners who suspect a pet has the disease should visit a veterinarian immediately. DeBey recommends using gloves to handle the animal.

No vaccines are available for tularemia. DeBey said the best way to prevent cats from contracting the disease is simple: keep them indoors.

“That is the best way, so cats won't be exposed to rabbits and to ticks,” he said. “For people who have cats but don't want to keep them indoors, the next best thing is to control ticks. Unfortunately, there's no way to control a cat from hunting rabbits since that's in their nature, but it's the risk you'll have to take with a cat being outdoors.

“Veterinarians need to consider tularemia especially when outdoor cats are ill or dying,” DeBey said. “As veterinarians we're a piece of the puzzle when it comes to preventing human disease.”

Although far more uncommon, humans can also contract tularemia by mowing the lawn.

“After an outbreak of tularemia on Martha's Vineyard in Massachusetts, it was found that lawn mowing was linked to increased risk of contracting tularemia, leading to the name 'lawnmower tularemia,'” DeBey said. “It is hypothesized that aerosolization of the organism occurs when the lawn mower passes over and contacts a rabbit carcass that is infected with the organism.”

Outdoor cats in the Manhattan area also are at risk of contracting cytauxzoonosis, another fatal, tick-transmitted disease with clinical signs similar to tularemia, DeBey said.

Brad DeBey, 785-532-4461, debey@vet.k-state.edu