Heartworm Prevention

What are heartworms and how can I tell if my pet has them?

Heartworms are internal parasites that infest an animal’s heart and vascular system. Their larvae enter your pet’s bloodstream through the bite of a common mosquito that previously bit a heartworm-positive dog. Those larvae then travel to the heart, grow into adults, and will begin to reproduce. If left untreated, heartworms are fatal.

They are most commonly seen in dogs, but can also be transmitted to cats. Only mosquitoes can transmit heartworms, so infection cannot pass between animals (dog-to-dog or dog-to-cat). People can become infected with heartworms by mosquitoes but it is very rare.

Lethargy, shortness of breath, coughing, and nosebleeds are all symptoms. Tragically, visible symptoms of heartworm infestation often don’t show for several months. This is why prevention is so important. Diagnosis of heartworm disease is typically done through blood tests. Cats are not routinely tested for heartworms because there is no definitive test or treatment for it.

Heartworm cycle chart

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