HeartwormDisease

What is heartworm disease?

Heartworm disease is a disease that is carried by mosquitoes that causes worms (that can be up to 1 foot long) to develop in the hearts and lungs of dogs (and occasionally cats). This disease was historically common in warmer areas of the country such as the southern states but it has become more widespread due to changes in climate and transport of animals from southern states into the northern states for rehoming. Heartworm has been diagnosed in all 50 states.

Why does heartworm disease matter?

In severe cases, heartworm disease can cause severe damage to the heart, lungs, or other organs of the body. This can manifest as a chronic cough, exercise intolerance, weight loss, and lethargy. The majority of pets with mild heartworm disease are not symptomatic. The earlier that a dog is diagnosed with heartworm disease, the less severe the long-term consequences of the infection will be.

When should animals be tested for heartworm disease?

Puppies should have their first heartworm test between the ages of 7-10 months. The heartworm test will then be performed annually to ensure that the heartworm preventative is working and to screen for tick-borne diseases. If your pet comes from an area with a high incidence of heartworm disease, your vet will likely recommend rechecking their heartworm test after 6 months and then annually ongoing. The reason for the recheck heartworm test after 6 months is that it takes an animal 6 months from the time of exposure to test positive for heartworm disease.

What is the treatment for heartworm disease?

The treatment for heartworm disease requires months of strict exercise restriction and 3 injections of an arsenic-derived compound into your pet’s muscle. The treatment is inconvenient, expensive, and painful for your pet so it is highly preferable that we prevent heartworm disease instead of treating it. The good news, however, is that the treatment is very successful if your pet does test positive for heartworm.

How do heartworm preventatives work?

Heartworm preventatives work by killing the immature stage of the heartworms. It takes approximately 51 days for the immature heartworm to develop into an immature adult, at which time the heartworm preventative will no longer be effective. This is why it is extremely important that you administer the heartworm preventative every month year-round. If you miss more than 1 dose of your dog’s heartworm preventative, you should restart the monthly preventative and recheck his heartworm test 6 months later.

Do heartworm preventatives also protect against intestinal parasites?

Many heartworm preventatives also kill intestinal parasites such as hookworms, roundworms, whipworms, and tapeworms. The exact intestinal parasite coverage depends on which product you use.