Rabbit Fever Kills Beavers in Utah, Experts Say It Can Affect Humans Too

In Utah, some beavers have died and authorities pointed to the rabbit fever as the cause of their deaths.

Authorities said that between March 23 and April 10, at least nine beavers unexpectedly died in various locations across Summit, Wasatch and Utah counties.

They said that the carcasses of two beavers were found at the Swaner Preserve & EcoCenter while another beaver was discovered at Midway.

On the other hand, another beaver, which was found near Birdseye, was submitted for disease testing to the Utah Veterinary Diagnostic Lab and the Utah Public Health Lab.

Authorities disclosed that all three beavers contracted tularemia, also known as rabbit fever, hare plague and deerfly fever.

Experts noted that this acute and fatal infectious disease is caused by a bacteria and this usually affects rabbits, hares and other rodents.

They said that the bacteria which causes the infection is known to be in the environment in many parts of Utah; however, it is unusual to see that many animals die from it at the same period.

So far, cases of tularemia are occasionally reported in animals as well as in humans across the United States but are normally isolated to a single animal or location.

The American Veterinary Medical Association said that tularemia most often affects lagomorphs (rabbits and hares) and rodents; however, it has been reported as affecting more than 100 species of wild and domestic mammals.

In North America, infections are most common in snowshoe hares, black-tailed jackrabbits, and eastern and desert cottontails.

Meanwhile, the infections in birds, fish, amphibians, and reptiles are relatively rare. Carnivores are susceptible, but they require high doses of the bacterium to become infected and rarely exhibit obvious signs of disease.

Domestic animals and humans are usually considered accidental hosts; however, outbreaks occurring in sheep in Canada, the United States, and Russia have resulted in high mortality.

Outbreaks have also been identified in commercially bred mink, beaver, and fox.

Experts also found out, although not common, that the disease has been identified in domestic cats. On the other hand, dogs appear to be resistant to infection, but may serve as reservoirs for the bacterium or maintenance hosts for the tick vector.

The global incidence of tularemia in humans is not well documented, but the number of reported cases has declined in recent years.

Transmission

Experts bared that ticks are the most important vectors of F. tularensis, transferring the bacterium between rabbits, hares, and rodents and serving as an interepizootic reservoir. Meanwhile, horseflies, mosquitoes, sucking lice, and biting flies may also serve as vectors.

When it comes to endemic areas, transmission to humans and other domestic vertebrates usually occurs via bites from infected arthropods, or the bacterium may enter scratches or knife cuts exposed to infected animal tissues.

Experts underscored that one can prevent tularemia by using insect repellent, wearing gloves when handling sick or dead animals and avoiding mowing over dead animals.