Tularemia Infection in Cats

The bacteria that causes tularemia is a gram-negative coccobacillus called Francisella tularensis. It can be diagnosed based on history, symptoms, blood tests, and blood cultures. The disease is treatable by the antibiotics streptomycin or tetracycline.

Tularemia, also known as rabbit fever, is a bacterial disease that occurs in humans and animals. It has been reported throughout North America, but is more prevalent in the western United States. Cats can become infected by eating small animals such as rabbits or voles that carry the bacteria in their system. They can also contract the disease if they are bitten by an infected tick or deer fly. When a cat becomes infected, they may display a variety of symptoms that include fever, abscesses, oral ulcers, weight loss, pneumonia, and septicemia. If your cat has recently eaten wild game and acutely develops any of the above symptoms, contact your veterinarian for an examination and diagnostic evaluation.

If your cat has become infected, you may notice a variety of different symptoms based on how the bacteria entered the body. The different signs you could see include:

• Fever
• Ulcers of mouth and tongue
• Gastroenteritis
• Swelling of regional lymph glands
• Anorexia and weight loss
• Cough
• Difficulty breathing
• Pneumonia
• Septicemia
• Depression

With each form or presentation of the disease, your cat will have a fever. The different forms of tularemia include:

• Ulceroglandular - skin ulcer and swelling of regional lymph glands
• Glandular - swelling of regional lymph glands without skin ulceration
• Oropharyngeal - oral ulcers, swollen lymph glands, gastroenteritis, and anorexia
• Pneumonic - cough, difficulty breathing, and pneumonia
• Typhoidal - generalized symptoms like anorexia and depression

Your cat could become infected with tularemia infection by a variety of methods. Depending on the mode of entry, the disease will display different characteristics:

• Ulceroglandular - This form develops when your cat is infected by a tick or insect bite. The area lymph glands become swollen, and a skin ulcer forms at the entry point.
• Glandular - Sometimes there will be no ulceration following a tick or insect bite. Regional lymph glands will still become swollen.
• Oropharyngeal - If your cat eats infected prey, you will see the oral ulcers and swollen area lymph glands. Your cat may also develop gastroenteritis and anorexia.
• Pneumonic - If your cat inhales dust or aerosols that carry the bacteria, they may develop a cough, difficulty breathing, and pneumonia.
• Typhoidal - This can occur from any mode of infection and includes general symptoms such as anorexia and depression.

It can be difficult to diagnose tularemia because it is rare and can be easily mistaken for other illnesses. If you suspect your cat has eaten infected prey or has been bitten by a tick or deer fly, and if you notice a sudden onset of symptoms like swollen glands, ulcers of the skin or mouth, gastroenteritis, coughing, pneumonia, or anorexia, contact your veterinarian.

Your doctor will collect a detailed history of potential exposure and any signs you have observed. Following a thorough physical examination, your veterinarian may collect blood samples. Routine blood work is usually not specific for this disease, so your doctor will likely screen for the presence of antibodies for the bacteria in the blood. Titers of antibody in the blood is adequate for a presumptive diagnosis of the disease. Most laboratories will not attempt blood cultures to isolate the organism because humans can become infected by this bacteria.

With a presumptive diagnosis of Tularemia, your veterinarian will begin treatment with tetracycline or streptomycin for 10 to 21 days depending on the severity of the infection and the type of antibiotic:

• Streptomycin - For pronounced cases, this is the preferred antibiotic due to efficacy and FDA approval for use. When using streptomycin, the course of treatment will last for 10 days.
• Tetracycline - With less severe infections, tetracyclines may be used. This antibiotic requires a 14 to 21-day course of treatment to ensure the bacteria is eliminated.
• Ciprofloxacin and other fluoroquinolones are not yet approved but show promise for treatment options.

Even if the symptoms resolve before the recommended number of days, be sure to complete the full course of antibiotics to help prevent a relapse. Animals generally recover fully without incidence.

Most patients recover completely from tularemia, but some symptoms may linger for several weeks. During recovery, be sure to provide supportive care for your cat. If your feline pal has gastrointestinal upset, make sure you offer easily digestible food and plenty of fluids. In the case of pneumonia or other respiratory difficulties, keep your cat comfortable and minimize excitement.

Tick control and use of repellents are important preventative measures to help protect your cat from tularemia infection.