Is Heartgard safe for collies?

You are likely aware that there is a shortage of Interceptor and Sentinel right now.  I have had several comments on my post about the Novartis shortages from people who are upset because they have a breed of dog who is sensitive to ivermectin and they feel that Interceptor and Sentinel are the only drugs that are safe to use for heartworm prevention for their dogs.  I wanted to write a post to explain why this is not true. (more…)...