Heartworm Season FAQ's

What is heartworm disease?
Heartworm disease is a serious and potentially fatal disease in dogs and cats. It is caused by a blood-borne parasite called Dirofilaria immitis.  Heartworm disease is more prevalent amongst dogs.

How do dogs and cats get heartworm disease?
Dogs and cats get heartworms by an intermediate host, the mosquito. The disease cannot be spread by direct dog to dog contact. 

When should my animal be tested?
At PVAH we recommend testing all adult dogs once yearly at their annual physical exam.  The heartworm test does not need to be done in the spring.  We recommend testing puppies at their one year annual exam. There is no heartworm test required for cats.

Where are heartworms found?
Heartworms are found all around the world, including the United States:

When should I give heartworm preventative?
Heartworm preventative should be given June 1^st through November 1^st for cats.  For dogs, it is recommended year round or April 1^st to December 1^st. 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.

What preventatives are recommended?

Interceptor: The active ingredient is milbemycin oxime.  It protects against heartworms, roundworms, hookworms, and whipworms. Interceptor is a flavored chewable tablet.

Heartgard Plus: The active ingredients are Ivermectin, pyrantel, and pamoate.  It protects against heartworms, roundworms, and hookworms. Heartgard Plus is given orally and comes as a pill, or a chewable beef flavored soft treat. 

Iverhart Plus:  The active ingredients are Ivermectin, pyrantel, and pamoate.  It protects against heartworms, roundworms, and hookworms. Iverhart Plus is given orally and comes as a chewable beef flavored hard treat.