Heartworms are exactly what they sound like – worms that live in the heart, and they are very dangerous because they can result in heart failure and even death. The good news is no pet needs to suffer from heartworm disease. It is easily preventable.

Mosquitos carry heartworms in a larval stage. When the mosquito bites a pet, the larvae end up in the pet's bloodstream. There the larvae must go through several different stages before they become adult worms that can attach inside the heart. This process takes about six months. This is why we can administer heartworm preventative only once a month. The medication kills any larvae transmitted during the previous month before they get to the adult stage. If you are late giving your dog his monthly preventative, consult your veterinarian. If several months go by with no prevention administered, a blood test should be performed before resuming the medication.
Yearly blood testing is important to be sure your dog did not get heartworm disease in spite of efforts to prevent it. Tardy administration of the medicine, and dogs spitting out or vomiting the medicine could allow a heartworm infection to take hold. Early detection is important because treatment for heartworm is very taxing because of the disease caused poor health of the infected dog. Heartworm is a classic case where an ounce of prevention is worth a pound of cure.