«Veterinarians can prescribe monthly preventive medications for a cat just as they do for dogs. (vetmed.illinois.edu)
Once the animal is dewormed, a veterinarian may also prescribe monthly preventive medication if available for that particular parasite or recommend a periodic exam and / or treatment protocol. (texvetpets.org)
Heartworm disease, however, can be expensive and difficult for your dog, so the best treatment is administration of a monthly preventive medication (which can also prevent other worm infections). (cesarsway.com)