Florida PantherNet

Another threat to a single, small, inbred population is disease. Inbreeding itself may have a negative effect on the immune system (O'Brien et al. 1985), making individuals more susceptible to disease. A small isolated population is at risk of becoming extinct from a contagious disease, although the risk is not as great in a solitary far-ranging species such as the panther as it is for more social species living in a smaller area. Any single population, even of a far-ranging animal, still faces some risk from disease.

In Kruger National Park in South Africa, 90 percent of the lions tested in the southern part of the park have been infected with tuberculosis as a result of eating infected Cape buffalo. In one area more than half of the adult lions have died from the disease (Discovery Channel Online, October 22, 1998).

Panthers have been exposed to several potentially serious diseases including feline calicivirus, feline panleukopenia virus, feline infectious peritonitis, and feline immunodeficiency virus (Dunbar 1994). One panther died of rabies, and another died of pseudorabies, a virus carried by wild hogs.

Between 2002 and 2004 several panthers became infected with feline leukemia virus (FeLV). It is suspected to have entered the population by a panther that ate an infected house cat. Three panthers died from the disease and two infected individuals were killed by intraspecific aggression before succumbing to the disease. Feline leukemia is transmitted through contact such as combat or breeding rituals and was quickly passed on among individuals in Okaloacoochee Slough State Forest. One surprising, and somewhat fortunate, outcome was how quickly FeLV killed panthers. Unlike FeLV in housecats, which may sometimes be carriers and not be affected by the disease, it is always fatal in panthers and only in a matter of a few short weeks of contracting it. This rapid period of contraction to death likely prevented FeLV from becoming a bigger problem throughout the entire panther range. As a result, FeLV is one more disease captured panthers are vaccinated against. Since July 2004 no other panthers have tested positive for FeLV.

Panthers are also infected with a number of parasites including hookworms. Hookworms can cause anemia and weight loss, and may contribute to death in domestic kittens.

Between 1986 and 1988, 30 percent of the panthers captured had antibodies for feline immunodeficiency virus (FIV) (Barr et al. 1989). Five of 19 panthers tested positive to FIV in 1992 (Roelke and Glass 1992). In 1998, one panther and one of the Texas cougar females introduced for genetic restoration tested positive, and for four of the cats the test results were inconclusive (Land and Taylor 1998). Both of the positive cats are residents of Everglades National Park. Both appear healthy and neither exhibit signs of the disease (Land and Taylor 1998). Although the significance of FIV to Florida panthers is currently unknown, in domestic cats FIV has a long incubation period and results in death (Roelke 1991). All of the panthers and cougars tested in 1997-98 were negative for feline infectious peritonitis and feline leukemia.

Captured panthers are vaccinated to help protect them from common domestic cat respiratory diseases (feline viral rhinotracheitis, feline calicvirus, feline panleukopenia) feline leukemia and rabies.