Written By Dr. Kelly Diehl
As summer gets into full swing with picnics, parades and pool parties, mosquitoes seem to be everywhere. These insects are not only annoying, they transmit many infectious agents, including Dirofilaria immitis, the parasite more commonly known as heartworm.
We’ve known about heartworm disease in dogs for more than 150 years. Treatment options for heartworm disease have come a long way, but the disease is still a big problem for dogs throughout the United States.
Heartworm disease is most common in areas with high mosquito populations and warm, humid weather. Incidence maps show the greatest number of reported cases in the Southeast, from North Carolina to east Texas, and along the Mississippi River. However, cases of heartworm disease have been reported in all 50 states.
According to the American Heartworm Society, infection rates can vary year to year because of different variables such as climate and infection rates of wildlife carriers. As more people and pets move around the country, infected dogs can carry heartworm to other areas of the country, raising infection rates. Because of the unpredictability surrounding exposure, the AHS recommends that all dogs get tested at least once a year for heartworm, and that dogs receive year-round preventives.
Many choices for heartworm prevention are available, and preventives are almost 100 percent effective, but preventive treatment failures can occur. A recent study done by the University of Tennessee tried to find out why.
The study team enlisted the help of a national hunting dog club. They asked members several questions about their dogs’ environment, their dogs’ activities, the type of preventive they used, and other heartworm associated questions. The study found several risk factors correlated with preventive failure. The more time a dog spent outside at dusk, at dawn or after dark, the higher the chance for preventive failure. The team also found that dogs that didn’t get tested at least once a year for heartworm also had higher rates of preventive failure. Researchers concluded that owners should try to decrease the amount of time their dogs spend outside when mosquitos are feeding, and also test their dogs for heartworm at least once a year.
Heartworm disease can be fatal if untreated, so prevention and early detection are crucial to helping our dogs live long, healthy lives. Now that summer is here, take care to give your dog their preventive medication as directed and test your dog for heartworm every 12 months. Our best friends deserve nothing less!