Tularemia is found in mammals and caused by the bacterium Francisella tularensis. The disease has been found in over 200 vertebrate species but most often infects rabbits and rodents. The major means of transmission is by blood-feeding arthropods (e.g., ticks, fleas).
Signs of the disease in infected cottontail rabbits are often variable or go unnoticed but may include lethargy, lack of coordination, and stupor.
Tularemia can produce severe, but localized, sporadic mortality in cottontail rabbits. Deaths have most often been found to occur in wild rabbits within enclosures. Mortality as a result of tularemia frequently occurs in jackrabbits as well. Beaver and muskrat die-offs have also be reported.
Tularemia is a life-threatening human disease characterized by fever, infected sores at point of entry, swollen lymph nodes, and general flu-like symptoms that progress rapidly. Anyone who has these signs of illness after known or potential exposure to disease should consult a physician. With prompt antibiotic treatments, few cases are fatal.
If tularemia is suspected, field necropsy is not recommended due to potential human risks. If the animal must be handled, appropriate precautions should be taken which include the use of rubber gloves followed by thorough washing with soap and water. Care should also be taken to prevent exposure to fleas and ticks that may be associated with the animal.