Georgetown Animal Clinic, PC

5155 Sheridan Drive
Williamsville, NY 14221



Heartworm Disease in Dogs


What is heartworm disease?

Heartworm disease is caused by a worm that lives in the heart.


How is it transmitted?

Heartworm disease is transmitted from dog to dog by a mosquito. It MUST go through a mosquito and can NOT go directly from dog to dog. EVEN INDOOR DOGS can get heartworm disease.


Do we have it in Western New York?

Yes. Absolutely. Anywhere there are mosquitos, there is heartworm disease.


What signs will my dog show when it gets infected?

Dogs will initially show NO signs. Once bitten by an infected mosquito, it takes 6 months for the parasite to grow up and migrate to the heart. After that the worms can live for months to years before a dog will show any signs of illness. Eventually the animal will go into heart failure and shows signs such as coughing, lethargy, exercise intolerance, weight loss, poor appetite, etc.


Is it fatal?

If left untreated, heartworm disease in dogs is fatal.


Can people get it? What about cats?

People can not get heartworm disease. Cats can get it but the disease differs from dogs. It is not as common in cats as dogs.


How do you test for heartworm disease?

An annual blood test is recommended for ALL dogs in this area. We test the blood for a protein that is produced by the worm. It is a very sensitive test.


Do I have to test every year?

Yes. AAHA and the AVMA standards of care recommend annual testing. The sooner we know about the infection, the easier it is to treat.


How do you prevent heartworm disease?

Monthly prophylactic medications include Revolution, Trifexix, and Iverhart and will prevent heartworm disease.


Can't I just give the preventatives to my dog if/when the test comes back positive?

No. The monthly preventatives will kill any "baby" heartworms (within 6 weeks of being infected by the mosquito) but once they become adults they are no longer susceptible to these mild, well tolerated medications.


What is involved in treatment of the disease?

First an animal must be staged to find out how far the disease has progressed. This involves blood work and chest x-rays and can be costly. Then the animal is treated with a series of injections that may have numerous side effects and requires hospitalization.