Parasites and Diseases

A Field Guide


caption follows
Spleen from healthy snowshoe hare (right) and hare with tularemia (left).

What causes tularemia?
  • Tularemia is caused by a bacterium known as Francisella tularensis.
  • There are two major cycles of this disease. The first occurs on land. Snowshoe hares are the primary host. The disease is spread from an infected hare to a susceptible hare by means of ticks. Ticks are only present on hares from May through September. The disease essentially disappears from October through April.
  • The second cycle occurs in water. Beaver and muskrats are the primary hosts. Infected animals die in a slough, pond or lake. As the carcass decomposes, large numbers of bacteria are released into the water. Susceptible animals are exposed when they drink or swim in the water.

Where does tularemia occur?
  • In Alaska, this disease is most common in the Interior.

What are the signs of tularemia?
  • In the latter stages of disease, hares become very slow.
  • Tularemia causes some internal organs (such as the spleen and liver) to become enlarged. Sometimes, white spots may also be seen on these organs.

How can I protect myself? [can infect people]  [can infect dogs]
  • People are susceptible to infection. Do not handle hares found dead or brought in by pets with your bare hands.
  • Contact of an infected pet's saliva or an infected hare's fluids into a cut, bite or abrasion on the skin may also allow disease transmission.
  • Wear protective gloves when gutting hares, muskrats and beavers, especially during spring/summer/fall.
  • Dogs and cats can die from tularemia. Infected hares are easy for dogs and cats to catch. Pets are infected when they eat the internal organs of infected hares. This disease is one reason why pets should not be allowed to roam free.

Can I eat the meat? [cook well]
  • Normal cooking temperatures kill bacteria in the meat. Therefore, it is safe to eat. However, human exposure typically occurs while gutting a hare.

Samples to collect
  • You can submit an entire hare, muskrat or beaver carcass (or just the spleen and liver).
  • To report an occurrence or to submit a sample for identification/analysis, contact the DWC Wildlife Disease Surveillance reporting hotline 907-328-8354, send an email to or visit your local ADF&G office.