Heartworm disease is a very serious disease in both cats and dogs, but the unique physiology of each species means that it is really two very different diseases. As you learn about the similarities and differences here, however, remember the bottom line: cats also need heartworm testing and year-round heartworm prevention.
Heartworm in Cats
Prevalence and risk:
Heartworm disease is a year-round health threat that has been diagnosed in all 50 states
Cats become infected through the bite of mosquitoes, which acquire heartworm larvae from infected dogs, coyotes, foxes and wolves.
Heartworms in cats are shorter than those in dogs, averaging 8-9 inches in length. Worms live 2-4 years.
Cats are a susceptible heartworm host, but are more resistant than the dog. Most worms do not survive to be mature adults, but still cause damage.
Approximately 75% of cats exposed to infective heartworm larvae become infected.
Most cats with infections have less than 6 heartworms; 1- to 2-worm infections are common.
Cats are highly sensitive to heartworms and, unlike dogs, do not need to harbor adult worms to become ill. Heartworm larvae can trigger a severe immune reaction called heartworm associated respiratory disease (HARD); this syndrome occurs in an estimated 50% of heartworm infections in cats.
Cats develop an asthma-like lung disease with respiratory distress and chronic coughing or vomiting. In cats with adult worms, the death of just one worm can cause sudden death.
Heartworm in cats is difficult to diagnose with blood tests. Further testing, including x-rays, may be required to make a diagnosis. Blood tests are recommended before a cat is started on a preventive.
There is no approved treatment for heartworms in cats.
Less than 5% of cats in the U.S. are on heartworm prevention.
The American Heartworm Society recommends year-round heartworm prevention. Prevention is easy and highly effective!
Info courtesy of American Heartworm Society