When should I give heartworm preventative?
Heartworm preventative should be given June 1st through November 1st for cats. For dogs, it is recommended year round or April 1st to December 1st. Heartworm disease is transmitted by mosquitos, and the treatment months are during mosquito season. Heartworm prevention works backwards, and protects your pet from heartworms for the previous 30 days from the day the prevention was given. Most heartworm preventatives have additional protection against intestinal parasites. Here at PVAH, we recommend giving it year round for the protection of intestinal parasites.