The American Heartworm Society (AHS) recommends annual heartworm testing and year-round heartworm prevention.
Here are five reasons why:
1: More than a million pets in the U.S. have heartworm disease. A look at the AHS heartworm incidence map* reveals that in most veterinary clinics in the U.S., a minimum of 1-5 heartworm cases per clinic were diagnosed in 2013, while numerous regions reported 100 cases per clinic or more. These reports do not reflect the status of the millions of dogs and cats that aren’t regularly seen by a veterinarian or tested for heartworm.
2: Heartworm disease has been diagnosed in all 50 states. Heartworms are spread by mosquitoes. While heartworm disease tends to be associated with regions that have warm, humid weather and high counts of pesky bloodsuckers, heartworm infection is widespread in most states of the country, including states like California and Arizona where the disease was once considered rare, thanks to dog mobility and the variety of mosquitoes that carry heartworm.
3: Both dogs and cats get heartworm disease. In dogs, adult heartworms that develop from heartworm larvae deposited by mosquitoes cause disease. Cats can also harbor adult heartworms, but it is more common in cats for heartworms to die before reaching maturity. However, even immature worms can cause respiratory disease in cats.
4: Heartworm disease can be fatal. Heartworm disease affects the heart, lungs and pulmonary blood vessels of pets and can be fatal to both dogs and cats. Annual testing and monitoring is important, because infected dogs can be successfully treated, and the earlier the better. There are no approved treatments for cats, but supportive care can help manage complications.
5: Prevention is safe, effective and cost-effective. The American Heartworm Society recommends year-round prevention for dogs and cats in the U.S., even in regions that experience cold winters. Heartworm preventives work retroactively, so an animal that acquires an infection one month must be given heartworm preventives in the months that follow to be protected. And with unpredictable weather patterns and the ability of hardy mosquitoes to survive in protected areas—as well as indoors—it’s difficult to predict when heartworms aren’t in season.
Fortunately, heartworm prevention is highly effective when given faithfully, and the year-round cost of preventing the disease in dogs is a small fraction of the cost of heartworm treatment.