Q: I have always given my dogs heartworm prevention (Revolution) on the first of every month. I recently got a new dog and he was just given his heartworm prevention on Feb. 15. I would like to give both dogs their heartworm prevention on the same day. Should I give my old dog his dose on March 1 and then wait until April 1 to give them both the next dose?
A: I would give both dogs their heartworm preventative on March 1. It won’t hurt the new dog to get the prevention two weeks early. All of the monthly heartworm preventatives are very safe and can be given more often than monthly if needed. It can be risky to give the medication at a longer interval than a month. It only takes one mosquito bite to transmit microscopic baby heartworms into your dog.
Dr. Susan M. Baker received her degree at the University of Florida in 1985 and practices veterinary medicine in Palm Beach County, Florida.