WHAT IS HEARTWORM DISEASE?

Heartworm disease is caused by a blood-borne parasites known as Dirofilaria immitis. It is a very serious and potentially fatal disease in our dogs. The parasites are found in mosquitos and once a mosquito that has the parasite bites the dog, the larvae migrate through the bloodstream towards the heart.  There they will stay to mature into adults and may begin to reproduce microfilariae within 6-7 months after the initial mosquito bite. The adult heart worms can live for up to five years in your dogs heart!

HOW IS IT SPREAD?

This disease is not spread directly from dog to dog. The disease needs a mosquito in order for it to spread. Even if your dog has long hair, it doesn’t prevent them from getting heartworms.

HOW DOES IT AFFECT MY DOG?

Once a dog is exposed to heartworm, it can take years before they start to display the signs of the infection. The most common signs from adult heartworm are weakness, dry cough, or shortness of breath, usually related to exercise. The microfilariae, or the immature heartworms, can also cause coughing and at times liver or kidney damage.

HOW CAN WE TEST FOR IT?

Heartworm testing is a blood test that is recommended annually.  Since it takes 6 months after the time of exposure for the test to accurately reflect the infection we generally begin testing young dogs if they are over 6 months or at their first annual visit as long as they have been receiving their heartworm prevention medication every month. If the screening does come back positive for heartworm, we follow the recommendations by the American Heartworm Society and verify the positive result with an second antigen test and will additionally test for microfilaria.  A second positive test, confirms the presence of heartworms and treatment needs to be started.

HOW IS HEARTWORM DISEASE TREATED?

Exercise restriction is a very important aspect throughout the treatment for heartworm disease. An antibiotic called doxycycline should also be started once the test results are confirmed positive.  This will take care of a bacteria that likes to piggyback along with the heartworm parasite. Thoracic radiographs (chest x-rays) are the next step to detect if the dog has an enlarged heart or any enlarged pulmonary vessels prior to starting the treatment. This helps predict how the dog may be able to handle the heartworm treatment itself. The heartworm treatment consist of three injections.  The first injection is given two months after starting the antibiotic.  One month later, the second two injections are given on consecutive days. These injections can be painful and dogs should receive pain medication to address any discomfort. Dogs are also placed on an oral steroid medication to help minimize the side effects of the treatment injections.   Throughout the treatment and for a eight weeks following the last injection dogs need to follow strict exercise restriction.  This amounts to about 5 -6 months in total for exercise restriction. Follow up heartworm blood tests are performed in 1 month and 6 months.

WHAT IS THE PROGNOSIS FOR HEARTWORM POSITIVE DOGS?

Even though this is a very serious disease, the prognosis with treatment is overall good.  Detecting and treating heartworm disease early generally results in fewer side effects and the prognosis improves.

HOW CAN THE DISEASE BE PREVENTED?

Prevention is safe and easy!  You simply need to give your pet a tasty chewable medication once a month.  Keeping your pet on heartworm prevention 365 days a year is essential for all dogs, especially those who have gone through heartworm treatment. Our preferred preventative is Interceptor Plus.