I have a question....

[molucass]

One of my friends just asked me this:

"I know if dogs have heartworm and you give them a preventative without knowing they have heartworms it can kill them I thought ... is that true???"

Does anyone know??? I've never heard that before, but I could be wrong.... So, if you know... Please let me know.

[binka_nugget]

I don't know if it could kill them but I think it could really harm them. The vet I went to to buy Sentinel made absolutely sure that my dogs were tested before he sold me the pills. He still asks everytime I go back.

[Shelteez2]

Yes it can. I'm not sure if this is with all types of preventative or just some.
I believe the reason it can is because if the dog has heartworms that are fully developed and living in the heart and then the dog gets the medicine to kill them it can cause a block in the aertery (sp).
I will try to find some more info for you if you'd like.