Heartworm is a potentially fatal disease, caused by a parasitic worm that invades the dog’s body when an infected mosquito bites the dog. This blood-borne parasite is known as Dirofilaria immitis. Adult worms are found in the heart, usually and rarely in other parts of the circulatory system. Adult heartworms may live up to 5 years and during this time, the female produces millions of offsprings called microfilaria. As many as 30 species of mosquitoes transmit heartworms, this threat is more intense the more south you go. All pets going to the United States should be on a preventative.
What are the symptoms of heartworm in a dog?
It takes several years before dogs show clinical signs of infection. It is rarely diagnosed when the dog is very young since it takes 5-7 months for the worms to mature worms. Adult worms cause disease by clogging the heart and other blood vessels, they also interfere with the valve action in the heart. The major signs are a soft, dry cough, shortness of breath and loss of stamina, weakness, nervousness. The signs are more noticeable following exercise.
How do dogs get heartworm?
The disease is not spread directly from dog to dog. Transmission requires the mosquito as an intermediate host. The spread of the disease coincides with the mosquito season (which can be year-round in many parts of the United States, but not so much in Canada). The mosquito usually bites the dog where the coat is thinnest.
What are the treatment options for heartworm?
First off, prevention is by far the best approach. There are several good prescription drugs that are available from your veterinarian. When some dogs are diagnosed, they usually have advanced heart disease and the prognosis for survival is low. One treatment option is to give an injectable drug to kill the adult heartworm. Several injections may be necessary to complete the task. Newer heartworm treatment protocols use a variety of drugs to kill the microfilariae.
Why is recovery and heartworm treatment challenging?
Complete rest is essential after treatment. The adult worms die in a few days and start to decompose. As they break up, they are carried to the lungs, where they are lodged in small blood vessels and are eventually reabsorbed by the body. This can take days to a month and can be dangerous, so it is absolutely essential that the dog is kept as quiet as possible and not allowed to exercise for 1 month following treatment. With the safe and affordable heartworm preventatives available today, no pets should have to endure this dreaded disease.
