Animals who found homes around the country because of hurricanes Katrina and Rita may inadvertently cause heartache for their new pet owners. An estimated 60 percent of the pets displaced by Hurricane Katrina are likely infested with heartworm, a potentially fatal, mosquito-borne illness, the American Heartworm Society (AHS) reports.
Research shows that heartworm is present in about 10 percent of cats, according to the AHS, which is a higher prevalence than feline immunodeficiency virus and feline leukemia, and the rate is likely even greater with animals from the Gulf.
In response, Dr. Kate Hurley, director of shelter medicine, at the University of California, Davis, Dr. Tom Nelson, president of the American Heartworm Society, and Professor Dwight Bowman, PhD, professor of parasitology at Cornell University, developed a protocol.
It recommends treating heartworm-positive animals with the standard heartworm preventative medication immediately after they've been diagnosed. This won't have an effect on the underlying disease, but it will kill heartworm larvae in the animals bloodstream and, thus, limit the spread of the disease by making the animal non-infectious to mosquitoes. The information is available on the AHS website, www.heartwormsociety.org.
Traditionally, the vast majority of heartworm cases throughout the country have been found in the wet and temperate climates of the Mississippi River Valley and the southeastern United States. But because of the Katrina refugees, some veterinarians now worry this insidious killer could begin making inroads in low-incidence areas such as the Pacific Northwest, California and the Southwest.
Dr. Nelson said its too early to tell whether displaced Katrina dogs will spawn significant heartworm outbreaks in other regions. Animals cannot be accurately diagnosed with heartworm for at least 6.5 months after infection, he says. In addition, the chances of transmission are dependent upon the climate of the area and time of year. Admittedly, regions that are not conducive to large mosquito populations are less likely to see heartworm outbreaks.
Dr. Bowman says a silver lining from the Katrina crisis is increased awareness about the dangers of heartworm.
Heartworm is caused when tiny roundworms are introduced into the bloodstream by infected mosquitoes. They embed themselves in the animals heart and in the blood vessels of the lungs, where they grow in size and produce offspring called microfilaria. As the worm population increases, the heart must work harder to pump blood. Eventually, the animal will exhibit the symptoms of congestive heart failure, including lethargy, difficulty breathing and coughing. Left untreated, heartworm can dramatically reduce an animals lifespan.
Headquartered in Batavia, Ill., the American Heartworm Society, www.heartwormsociety.org, was founded in 1974 to facilitate and encourage the generation and dissemination of information about heartworm disease.