Heartworms are a serious disease of an animal's cardiopulmonary (kar-dee-o-PULL-mah-nare-ee) system and generally affect dogs. Worm larvae (LAR-vee) are carried by mosquitoes which ingest the infected blood of one animal and transfer the disease to healthy animals through bites.

How often is too often when it comes to your pet's vaccinations? It's a question more and more pet owners are asking these days. Mounting debate about the need to vaccinate animals annually, along with concerns about a possible link between vaccines and rare cancers, may leave many pet owners confused about how often to visit the vet for vaccinations.