Why Does My Pet Need To Be On Heartworm Prevention?

Heartworm disease is a serious and potentially fatal disease in dogs.  It is caused by a ten-inch long parasite called Dirofilaria immitus.  These worms live in the heart and adjacent blood vessels of infected dogs. 

How are heartworms transmitted?

The disease is transmitted when mosquito's carry microscopic baby heartworms from one dog to the next.  It takes six months after your pet is bitten by an infected mosquito for him to have adult worms in his heart.

My dog stays mostly inside and has a thick hair coat.  Can he still become infected with heartworms?

Yes!  A thick hair coat will provide your pet with some protection, but it is not guaranteed because the hairs on the face and ears are thin enough that mosquitos can easily reach the pet's body to feed.

How common is this disease?

Heartworm disease occurs in 66-100% of dogs exposed to mosquitos and who live in endemic regions.  There are many different subspecies of mosquitos, each with their own individual habitat (environmental) preference.  Some mosquitos live almost completely indoors.

How often does my pet need to be on medication and for how long?

Dogs need to be on heartworm preventive on the same day each month YEAR-ROUND.  Unlike vaccinations, which are boostered periodically, heartworm prevention works only as long as you continue to give it.  Should your pet be off of the medication, your dog will be at risk for getting heartworms.  Prevention is safer and less costly than treatment.  Do not stop giving preventive in the winter months.  Dogs need to be put on preventive for their entire lives.

Why does my pet need to be tested before he can be given the medication?

It is important to determine if your pet is infected with heartworms because some heartworm medications are dangerous to give to dogs with heartworms.  Dogs that have heartworms should not be put on heartworm preventive unless you have talked to a veterinarian first.  Should your pet test positive for heartworms, we strongly recommend that he be give treatment to kill the adult worms and then put on preventive medication.