Heartworm positive after negative test and a year on prevention meds

My dog was acquired through a reputable rescue last August. He had all vet work done in July of 2020 and tested heartworm negative. The rescue had him on prevention meds and we continued with that. He just had his one year Gotcha Day anniversary checkup and blood work and he is heartworm positive. A second test confirmed the result.

Has anyone else had this happen? The vet said he probably was bitten by an infected mosquito around the time the rescue got him, so he would have tested negative then and positive now as it takes around six months for an infected dog to test positive.

We have a treatments plan that is appropriate for an older dog. In this case the dog is a fifteen year old Golden Retriever. Has anyone with an older dog gone through this? The vet says she sees this situation occasionally but that doesn’t make it any easier for me or my dog.

No experience with this, just wanted to offer up some Jingles!

1 Like

This is why many hospitals started doing 6m recheck HW tests on southern transport dogs.

Its a bummer but I bet has a low worm burden and will do well. Upside is keeping a 15 year old quiet after treatment is easier than a younger dog!


I’m so sorry that happened and he has to go through the treatment after having all the right things done!

Jingles for him and you!