April is National Heartworm Awareness Month, and pet owners should know that heartworm disease doesn’t play favorites—it can strike both dogs and cats. But how it affects them and how they respond is very different. While dogs are often thought of as the primary victims, cats face serious risks, too, even if they stay indoors all the time. At Fayetteville Animal Clinic, we believe pet owners should understand the unique ways heartworm impacts each species so they can make informed choices about prevention and care.


Heartworm in Dogs: The Natural Host


Dogs are known as the natural host for heartworms, meaning the parasite thrives inside their bodies. Once infected, the larvae mature into adult worms and multiply rapidly. Adult heartworms can live 5–7 years in dogs, and they grow up to a foot long. Heartworm-positive dogs may carry dozens, sometimes hundreds, of worms. Over time, this heavy parasite load can lead to:


Fortunately, while heartworm treatment is intense, costly, and requires careful veterinary supervision, it is available for dogs. Treatment is especially effective when the disease is caught early.


Heartworm in Cats: The Stealthier Threat


Cats, on the other hand, are atypical hosts. While heartworms don’t thrive in cats as easily as they do in dogs, infection can still be extremely dangerous. Cats typically have fewer heartworms, sometimes just one or two. However, even a single worm can cause severe complications. Heartworms in cats often trigger intense inflammation in the lungs and arteries. Common signs of heartworm disease in felines include:


What makes heartworm in cats especially concerning is that there is no approved treatment for adult worms. Prevention is truly the only reliable safeguard.


Do Both Pets Need Heartworm Prevention? Yes.


Whether your pet barks or purrs, they need protection from heartworm disease. Both dogs and cats face the risk of heartworm infection, especially since heartworm-carrying mosquitoes easily enter homes and bite pets regardless of species. Veterinarians recommend year-round prevention for heartworm. Monthly chewables, topical solutions, or heartworm injections (for dogs) are all options for protecting your pet.


For dogs, annual heartworm testing should be performed during a wellness exam, even if they’re on prevention. Testing for cats is more complex. Blood tests and imaging can detect exposure, but because worms are fewer in number, detection is trickier. This is yet another reason why prevention is vital for kittens and adult cats.


Protect All Pets from Heartworm Disease in Fayetteville, TN


Dogs and cats may experience heartworm disease differently, but the outcome can be devastating in both. The good news is prevention is simple and accessible. At Fayetteville Animal Clinic, we can work with pet owners to protect every member of your furry family in Fayetteville, TN, and nearby areas like Huntsville and Petersburg. Not sure if your dog or cat is protected? Book an appointment to discuss heartworm testing and prevention options for your pet.