Heartworms

Chew On This

Cade B. Coppenbarger, DVM ****  Monika Payne, DVM

Heartworms

(Dirofilaria immitis)

Heartworms are one of the most important parasites in dogs and cats.  Heartworms, if left untreated, are almost always fatal.  Heartworms are found throughout the United States and Canada.  Heartworm disease is especially common in this Southern part of Oklahoma.

Heartworm Disease is spread by mosquitos after ingesting blood from an infected dog.  The microfilaria (“baby heartworms”) is transmitted to another dog or cat when the mosquito bites it.  Once the heartworms mature they begin reproducing additional microfilaria.  A mosquito must ingest the microfilaria before they can become infectious.  The mosquito has to then inject the heartworm larvae into the susceptible pet.  It takes 3 to 6 months for adult heartworms to develop in a dog after an infected mosquito bites it.

Heartworms occur in all breeds of dogs: large and small, short haired and long haired, inside dogs and outside dogs.  Heartworms also are known to infect cats.  Diagnosis of heartworms is by blood testing to detect baby heartworms in the blood.  A special test to detect occult heartworm disease is sometimes required when heartworms are suspected, even if the initial screening test is negative because a small number of dogs may have adult heartworms but yet have no microfilaria in the bloodstream.

Treatment is very successful when the disease is detected early.  The adult worms are killed with an injectable drug given in a series of 2-3 injections.  A few days later the worms begin to die and are carried by way of the bloodstream to the lungs where they lodge in small blood vessels.  They slowly decompose and are absorbed by the body over a period of several months.

The good news is that heartworms are easily preventable.  In this area heartworm prevention should be given all year long.  The prevention is easy.  Pills or chewable treats given monthly to prevent the disease is far easier and less expensive to give than the alternative which is treating the disease.  As the old saying goes, “an ounce of prevention is much better than a pound of cure.”

Year round prevention is the best bet.  Mosquitoes can survive the winter inside your home.  A mosquito which is carrying heartworm disease is as much of a threat to your pet in the winter as in the summer.  Only one bite can infect your pet.  Also by giving monthly prevention you stay on schedule and are less likely to forget to give the prevention.

Heartworm disease is a devastating and often fatal disease that can easily be prevented.  If the health and well being of your pet is a high priority to you then take time once a month to give your pet a treat that prevents heartworm disease.  Your pet will definitely thank you.