YES!!! We live in Louisiana…and we have mosquitoes inside and outside 12 months out of the year…. so we recommend that every month of every year you have a DOG OR CAT that they ALL have heartworm prevention. eartworm disease in cats is very different from heartworm disease in dogs. The cat is an atypical host for heartworms, and most worms in cats do not survive to the adult stage. Cats with adult heartworms typically have just one to three worms, and many cats affected by heartworms have no adult worms. While this means heartworm disease often goes undiagnosed in cats