Alabama Pets Lead the Nation in Heartworm Incidence

American Heartworm Society survey shows sharp incidence increase among Yellowhammer State Pets

WILMINGTON, Del.--()--There’s sobering news for Alabama’s pet owners: the Yellowhammer State holds the dubious distinction of having the highest rate of heartworm disease incidence in the country. According to the American Heartworm Society (AHS), which conducts a nationwide incidence survey every three years, Alabama jumped from a #7 ranking in the last survey to their current #1 position.

“We know that far too many pets in Alabama are affected with heartworm disease”

The latest AHS survey is based on testing data from the 2013 calendar year. More than 4,500 veterinary practices and shelters in the nation participated, contributing data from an estimated 3.5 million patients. Results of the survey are being released to help pet owners better understand the threat of heartworm disease, both nationwide and in their area.

The state-by-state breakout of the findings shows that Alabama came in first place, followed by Louisiana, Mississippi, Texas, Arkansas, South Carolina, North Carolina, Tennessee, Georgia and Oklahoma. Three years ago, the top three states were Louisiana, Mississippi and Texas.

The American Heartworm Society bases their rankings on the average number of heartworm-positive dogs per clinic. During the 2013 calendar year, Alabama veterinary practices reported an average of 90 heartworm-positive dogs per clinic; this compares to 31 dogs per clinic in 2010.

“We know that far too many pets in Alabama are affected with heartworm disease,” states AHS board member and veterinarian Chris Rehm, DVM, who practices in Mobile. “However, we also know that veterinarians and pet owners have the power to prevent this deadly disease.” In fact, in a questionnaire completed by veterinarians participating in the AHS Incidence Survey, veterinarians who noted that heartworm incidence had increased in their practice areas said the leading reason was pet owners not administering heartworm preventives on time and as directed.

Heartworm disease affects pets nationwide
Heartworm disease has been diagnosed in all 50 states, and states in the southeast quadrant of the U.S. historically have led the nation in heartworm incidence. Heartworm disease is spread via mosquitoes, and warm-weather states with high mosquito populations face significant disease risk. High local populations of infected dogs and wildlife (coyotes and foxes carry heartworm) also increase the risk of heartworm to unprotected pets.

Treatment for heartworm infection in dogs is available, but is costly and requires strict supervision by both veterinarians and owners, as well as several months of cage confinement. Dr. Rehm notes that while dogs with heartworm disease can be successfully treated, the infection can cause permanent damage to the pet’s organs and circulatory system. Meanwhile, there is no approved treatment medication for heartworm disease in cats.

The annual cost of prevention typically runs less than ten percent of the cost of treatment. In addition, a number of heartworm preventives also protect pets against intestinal parasites and fleas as well as heartworms.

“Heartworm disease is a deadly—but preventable—disease,” Dr. Rehm concludes. “That’s why the American Heartworm Society recommends that pets be tested for heartworm each year and that dogs and cats be put on preventive medicine for heartworm year-round.”

For more information on heartworm disease and the AHS Heartworm Incidence Survey, visit


For the American Heartworm Society
Sue O'Brien, 612-305-6116

Release Summary

Alabama leads the nation in incidence of deadly heartworm disease in pets, according to a recent incidence survey conducted by the American Heartworm Society.

American Heartworm Society