Revolution

My dog has been on the heartworm preventative Revolution for 3 years.  I started him on this when he was only 5 mos. old and he has never missed a dosage.
On my dog's last yearly checkup I went to a different veterinarian than usual because I was out of town.  They told me that my dog had a "slight positive" for heartworms.
I then brought my dog back to my regular veterinarian to get a 2nd opinion.  I did not believe the results since my dog never had missed the Revolution on the first of each month.
My regular veterinarian told me that my dog was positive for heartworms also.
They recommended that I keep my dog on Revolution to get rid of the heartworms.  ?!?!!?
This Revolution did not even prevent them.
The veterinarian told me that it was possible that my dog was positive for heartworms during his first 5 month checkup (3 yrs ago) but that the test did not show up positive because they had not set in yet.  He also told me that it was possible that the lab results had been misread in the 2 yearly checkups that he had since.  He is insistent that this is not a big deal and that I need to keep my dog on Revolution.  This dog is very important to me.  I do not want to be playing games with this veterinarian just because he may have made a mistake.
Should I keep my dog on Revolution or do something else.

Thanks,

[Jaybay]

I was OK with your vet until he told you that your dog's heartworms are "not a big deal."  If this were my dog, I would find a new vet.  

Med Help has a free Ask-A-Vet forum, and I think this question shoud be posted there.  One of the vets can give you a professional opinion regarding the effectiveness of Revolution and the recommended treatment for your dog.  Maybe I'm missing something, but based on what you write I'm not very impressed with the vet you're using now.

Keep us updated on your pup's progress.  Heartworm cases crop up here occasionally and I'm interested to hear what treatments are available.  I hope he comes through it all right.  :-)