Took my 2 to the vet this morning for their annual check ups & vaccines. He told me that it's been found that the Proheart heartworm vaccine not only protects for 12 months but it also works backwards for 5 months. He must have read the WTH are you talking about? look on my face because he went on to explain that it also kills any heartworm infection contracted in the 5 months prior to having the injection. That was a big relief to me because they were about 1 month over for their vacs & I was a bit concerned about the heartworm but it turned out I had nothing to fear. 
Does anyone else use Proheart? Have you heard similar claims from your vet or supplier?
Does anyone else use Proheart? Have you heard similar claims from your vet or supplier?