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How do dogs get heartworms, and can my other dogs catch them?

Updated on September 23rd, 2025

Pet's info: Dog | Mixed Breed | Male | unneutered | 11 years and 5 months old | 76 lbs

I took my dog too the vet yesterday they told me he has heart worms. He has a few other things wrong too but I heard from other people heart worms in very dangerous i'm just wondering if you by any chance know how a dog gets heart worms. I've very worried about him & my other dogs & is heart worms contagious like can my other dogs get it from him?

1 Answer

Most Helpful Answer

Answered By Laura Johnson VMD

Veterinarian

Published on July 15th, 2017

Hi, I'm Dr. Johnson. Thanks for using Petco Pet Education Center, formerly Petcoach. Poor Midnight

Yes, heartworm disease is serious. Dogs get heartworm from being bitten by an infected mosquito. The mosquito injects microfilaria (baby heartworm) in to the skin when they bite the dog. It can then take 6 months to travel from the skin to the pulmonary artery. If they get a lot of heartworm they back up in to the heart (Caval syndrome). That is very serious because the adult worms have to be extracted from the heart via the jugular vein.

Your other dogs can not get it from Midnight, only from a mosquito. You should have all your dogs tested then started on heartworm prevention.

The gold standard of treatment is injectable adulticide as 3 injections. One is given then the other 2 a month later 24 hours apart. During treatment and 2 months after the 3rd injection the dog has to be strictly cage rested. The major risk of treating and HAVING heart worm is sudden death from clots to the lungs.

Talk to your Vet about treatment options.

I wish you the best!

2Pet Parents found this answer helpful

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