Summer is finally here, and along with it, our nemesis: the mosquito. Dog owners are well aware of the hazard this pest poses as a carrier of heartworm disease, but many cat lovers don't realize that our feline family members are at risk as well. Recent studies have shown that heartworm infection is not the rarity in kitties that it was once thought to be. Rather, in regions of the country where heartworm is prevalent, up to 25% of unprotected cats show evidence of infection at some point in their lifetimes. This makes the infection far more common than Feline Leukemia virus (5%) or Feline Immunodeficiency Virus (6%).
Heartworm behaves differently in cats than in dogs, affecting the lungs more than just the heart muscle. The constellation of symptoms that occur in cats is known as Heartworm Associated Respiratory Disease (HARD) and is often mistaken for feline asthma, allergic bronchitis or other respiratory illness. Symptoms can include coughing, difficulty breathing, rapid heart rate and collapse. In severe cases, sudden blindness, convulsions or sudden death have been known to occur, or the signs may be as vague as weight loss, lethargy, anorexia and vomiting.
Further complicating the issue is that the relatively quick and accurate screening tests that exist for canines are not validated for cats; negative antigen and antibody tests do not rule out the disease. A positive test is considered significant, however, and testing should be considered in any kitty that exhibits the signs described above.
Since the mosquitoes that transmit the disease can be anywhere, indoor cats are considered to be as much at risk as outdoor kitties. Prevention is considered key to feline wellness since current treatments can be risky, especially if a kitty's health is already compromised. Different options for heartworm prevention, both oral and topical, are available and should be discussed with your veterinarian. If you'd like to learn more, please visit the American Heartworm Society or the American Association of Feline Practitioners.
You're also welcome to call the healthcare staff at Muddy Creek with any questions you may have about your feline friend.
Dr. Sylvia Reiser is an associate veterinarian at Muddy Creek Animal Care Center in Rowley, MA. Dr. Reiser is also a member of the American Association of Feline Practitioners.