Causative agent: there are many different strains of leptospira that can cause disease (9).

Leptospirosis can cause disease in all farm animal species and in humans (9). Wild animals including dogs, skunks, deer, rats, bats and other rodents can carry the bacterium (9). Leptospirosis is often associated with wet areas having abundant surface water. The source of infection is usually from drinking water that is infected with the bacterium. Many animals can be carriers without developing the disease.

A serological survey of bison in Yellowstone National Park demonstrated that 1 to 7% of bison had titers to various strains of leptospirosis (26). Leptospirosis in bison has been reported (8).

Clinical signs:
The clinical signs of leptospirosis in bison have not been reported (8,26). Leptospirosis can cause a wide variety of syndromes in cattle including: septicemia, interstitial nephritis, abortion and mastitis (9). Many infected cattle don’t show any signs of disease (9). Cattle with acute leptospirosis develop a high fever, depression, anorexia, hemolytic anemia, bloody urine, jaundice, increased heart rate, labored breathing, and bloody colored milk (9). Leptospirosis is associated with a high case fatality rate in cattle (9).

Urine may be submitted to a diagnostic pathology laboratory for bacterial culture and identification. Blood may be submitted to a diagnostic pathology laboratory for serology. Paired samples are required to demonstrate the presence of a rising titer of antibodies to leptospirosis.

There have been no treatment protocols described for bison (8). In cattle, treatment must be instituted as early as possible, before there is irreparable damage to the kidneys (9). In cattle response to treatment is poor (9). In cattle, broad-spectrum antibiotics are used to treat leptospirosis (9).

There have been no prevention programs reported for leptospirosis in bison. There are a number of commercially available vaccines approved for use in cattle. None of these have been approved for use in bison. In areas where leptospirosis is endemic cattle are vaccinated annually.


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