The parasite is most commonly found in the Southeast and Midwest United States and is very prevalent in Illinois, where mosquito season includes late spring, summer, and early fall. In cats the signs of heartworms can be vague and can mimic other feline diseases, making diagnosis difficult. Many cats are able to clear the infection before the worms reach the heart. Other cats can appear healthy and then suddenly die from heartworms. Unfortunately, heartworms can cause a lot of damage before the pet shows any clinical signs.
Several drugs prevent heartworm infection.
Heartworm medication for cats has recently been approved. The drugs kill the immature form of the heartworm before it reaches the heart. These drugs must be administered monthly or daily, depending on the type prescribed, throughout mosquito season. Veterinarians can recommend an appropriate drug regimen depending on area. If the pet is found to have heartworms, treatment to eliminate the adult form is available, but it is very difficult and can be quite harsh on the pet.