No Hiatus for Heartworm

WILMINGTON, Del., Sept. 20, 2012 /PRNewswire/ -- It will take more than the worst drought in decades to significantly reduce the threat of mosquito-transmitted diseases such as heartworm disease, warns an entomologist speaking on behalf of the American Heartworm Society (AHS).

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According to Tanja McKay, PhD, an entomologist from Arkansas State University, pet owners need to avoid the dangerous—and erroneous—conclusion that drought conditions eliminate the threat of mosquitoes and, thus, mosquito-borne diseases such as heartworm disease. What owners overlook is that rainfall is not the only source of water in which mosquitoes can breed.

"I live in Jonesboro, and we've experienced a severe drought this summer," Dr. McKay explains. "But because we have irrigated rice fields, and runoff from the irrigation sites, we continue to have large numbers of mosquitoes."

Additionally urban areas, where both people and pets are concentrated, harbor manmade mosquito breeding grounds. "Across the country, there are thousands of miles of underground storm drain systems that are perfect places for mosquitoes to breed and multiply," she states, adding that watered lawns and gardens also provide sufficient standing water for mosquito reproduction.

The recent outbreaks of mosquito-transmitted diseases such as West Nile offer sobering evidence that mosquitoes are resilient and adaptable. According to Dr. McKay, multiple species of disease-carrying mosquitoes are known for their adaptability to different kinds of conditions. "Some mosquitoes breed and hatch in low-lying areas that flood when it rains, while others prefer old tires, tin cans and birdbaths," she explains. She notes that one reason some species of mosquitoes thrive during a drought (and in the subsequent year) is that their predators and competitors die off from lack of water.[1]

The American Heartworm Society recommends that all pets be administered heartworm protection for 12 months a year, citing scientific evidence that heartworm disease presents a persistent threat.

"While some reports have referred to lower mosquito populations as the drought's 'silver lining,' the reality is that mosquitoes are surviving—and reproducing—at sufficient levels to sustain the threat of heartworm disease transmission," warns AHS president Wallace Graham, DVM. "We urge owners to remain vigilant about heartworm protection and remember that it only takes one bite from an infected mosquito to transmit a disease that can threaten the life of a pet."

For more information on heartworm disease in pets, visit www.heartwormsociety.org/think12/.

About heartworm disease
Heartworm disease is one of the leading pet health problems in the United States; it is estimated that approximately 1 million U.S. pets are heartworm-positive. The disease is transmitted through the bite of mosquitoes carrying the parasite. Left untreated, heartworm infection can lead to severe lung disease, heart failure, organ damage and death. Both dogs and cats can develop heartworm disease.

About the American Heartworm Society
The mission of the American Heartworm Society is to lead the veterinary profession and the public in the understanding of heartworm disease. Founded during the Heartworm Symposium of 1974, the American Heartworm Society aims to further scientific progress in the study of heartworm disease, inform the membership of new developments and encourage and help promote effective procedures for the diagnosis, treatment and prevention of heartworm disease. 

[1] Kaiser J. Drought portends mosquito misery. Science. 2003; 301:904.

SOURCE American Heartworm Society