Heartworm FAQs

Heartworms are potentially fatal. Heartworms are parasites that destroy vital organs. Fortunately, heartworms can be easily prevented and are often treatable. At Fairway Knolls Veterinary Hospital in Bloomington, we offer heartworm treatment and prevention for dogs and cats.


What Causes Heartworms?

Heartworms are transmitted to dogs and cats through infected mosquitoes. Once the parasite is in the bloodstream, it will live in the heart, circulatory system, and lungs. Adult female heartworms have millions of offspring, known as microfilariae. When an infected mosquito bites a dog, they transmit the microfilariae.

What Animals Can Get Heartworm?

Heartworm is most common in dogs. Dogs are the preferred host and the worms can complete their life-cycle inside the dog. Cats can contract heartworm as well, but the heartworms will rarely grow to their adult size. They are not able to reproduce in cats. Heartworms can also affect other mammals, including ferrets. Cases in humans are exceedingly rare.

How is Heartworm Diagnosed?

Heartworm can cause several different symptoms. These symptoms include coughing, fatigue, inability to exercise, weight loss, and loss of appetite. Most dogs will not show any symptoms until the disease is in a later stage. Two tests can be used to diagnose heartworm. The first and most common test checks for adult heartworms. The second test is often used to confirm a positive test and tests for microfilariae. Testing is usually performed before starting a heartworm preventative and once each year while on the heartworm preventative.

How is Heartworm Treated?

Heartworm is treated with a series of injections for dogs. These injections kill adult heartworms. The dog must rest for one month after the injections because the dead heartworms will travel to the lungs. The dog my cough for up to two months after the treatment if it was heavily infected. Antibiotics may be administered to prevent infections caused by the bacteria in the heartworms.

Cats are not a natural host for heartworms, but they can still contract them. Cats may have no adult heartworms or one adult heartworm. The heartworm can still damage the internal organs. There is no approved treatment for heartworm in cats.

How is Heartworm Prevented?

The most common heartworm preventative is a monthly chewable tablet. There are also topical preventatives and a six-month injection that can be given by our veterinarians. Many preventatives also include flea and tick prevention.

Can Heartworm be Passed From Dog to Dog?

Heartworm can only be transmitted through mosquitoes, which are known as intermediate hosts.

Get Heartworm Prevention and Treatment in Bloomington, IL

If you are a pet owner living in or around Bloomington, our team at Fairway Knolls Veterinary Hospital can meet your pet’s heartworm prevention and treatment needs. Call us today at (309) 663-1414 to schedule an appointment with one of our veterinarians.


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