February 20, 2012
Posted in Pet Health

Heartworms are transmitted to your dog by a bite from a mosquito that carries the heartworm larvae.  The heartworm larvae, also known as microfilaria, enter your dog’s skin where they develop and then migrate to your dog’s heart where they continue to mature.  A fully-grown female heartworm can be over 12 inches long. Heartworm can also be found in an infected dog’s lungs and blood vessels.  A heartworm infection cannot be detected until 5 to 7 months from the initial infection.

Symptoms of Heartworm Disease

The severity of symptoms in a dog infected with heartworm depends upon the number of heartworms present, as well as the activity level of the dog; a more active dog will show more symptoms of heartworm disease than a more sedentary dog.  While some dogs show no signs or symptoms, a dog with heartworm may have any of these symptoms: cough, fatigue or exercise-intolerance, weight loss, labored breathing, and loss of appetite. It can sometimes be years before a dog will show symptoms of heartworm disease. Severe cases of heartworm can lead to right-sided heart failure in the infected dog, and heartworm disease can ultimately be fatal.

How is Heartworm Disease Treated?

The primary goal of heartworm treatment is to kill the adult heartworms and the microfilaria, without harmful effects to the infected dog.  Treatment will be tailored to the dog, based upon the dog’s health and the stage or severity of the heartworm disease.  The most common treatment for heartworm is a series of injections of a drug called an adulticide, along with rest during the recovery period which can last up to two months.   The injections can be quite painful to the dog, and there is danger of pulmonary embolism caused by pieces of the dead and dying worms.   In some cases, the heartworms may be surgically removed.

After completion of heartworm treatment, the dog should continue on a regular monthly heartworm preventative to kill any remaining circulating microfilaria.

Given the cost and inherent dangers of heartworm treatment, it is much more effective to prevent rather than treat heartworm.  The American Heartworm Society recommends year round heartworm prevention.

Heartworm: Learn More

Want to learn more? Our PetMeds Click and Learn provides even more information about the importance of heartworm prevention.

Related posts:

1. Why is heartworm prevention so important?
2. Heartworm: Are Cats At Risk, Too?
3. What to know about heartworm disease
4. How can I tell if my dog has heartworm?
5. Heartworm medication is important

Tags: heartworm disease, heartworm in dogs, heartworm prevention, heartworm treatment