I have been hearing lately about a disease that’s new to me – tularemia. What is tularemia?
Tularemia is a bacterial disease caused by Francisella tularensis and is often referred to as “rabbit fever.” Tularemia is most commonly found in rabbits and rodents, and it survives by creating tumor-like masses and abscesses in the victim animal’s liver. It is a disease that is not seen at all in the United Kingdom, Africa, South America, or Australia. In the United States, tularemia cases are scattered around the country. It is most commonly seen in the late spring and summer.
Tularemia is an uncommon infection in dogs, but cats can be exposed if they kill and/or eat an infected rabbit or rodent.
How is tularemia transmitted?
Infection with Francisella tularensis can occur in several ways:
- Ingestion of the tissues or body fluids of an infected animal. After ingestion, the lymph nodes in the head, neck, and GI system collect the bacteria. From there, systemic infection follows.
- Contaminated water.
- Some blood-sucking bugs – ticks, midges, fleas, or mosquitoes. – can transmit tularemia.
- Skin contact. The bacteria create a blister in the skin 3-5 days after contact. The blister ulcerates 2 – 4 days later, then the bacteria enter the lymph system, spreading to the rest of the body.
Once the bacteria are in the lymphatics, the organism can be found in the lungs, liver, spleen, and the bone marrow.
What are the signs of tularemia infection in dogs?
Tularemia generally causes an acute illness with high fever (40 – 41º C; 104 – 106º F), large painful lymph nodes in the head and neck, abdominal pain, jaundice (yellowing of skin, mucous membranes, and the whites of the eyes), and organ system failure.
How is tularemia diagnosed?
In order to diagnose tularemia, other diseases that cause sudden onset fever, enlarged lymph nodes, and lethargy must first be ruled out. These include bubonic plague and pseudotuberculosis.
Diagnostic tests typically include a complete blood count (CBC), a blood chemistry panel, and a urinalysis. Testing will reveal a high white blood cell count, low blood sugar, low blood sodium, and a high blood level of bilirubin. There may also be blood in the urine.
Unfortunately, there is no single, simple test for tularemia.
Can tularemia be treated?
Yes, tularemia can be treated, but it requires aggressive treatment including hospitalization with good supportive care (intravenous fluid therapy, antibiotics, etc.). The key to successful treatment is EARLY intervention. Even with early diagnosis and treatment, the death rate among dogs with tularemia is high.
Can I catch tularemia?
Tularemia has a high zoonotic potential, meaning it can infect humans. A bite from an infected dog poses a risk to humans. When hospitalized, these dogs are isolated and the veterinary team will wear protective gear during treatments.