Hi, I'm new to the forum, but not to dogs, although I have been away from Collies for a while. I have Riley, who will be 4 months old this Friday. I've had him about 5 weeks now (he was a rehome rescue) and he just finished his last round of shots. While I was at the vet's office I went ahead and requested a collie safe heartworm preventative because I know that collies can't (or shouldn't) have Ivermectin (and Riley hasn't been tested yet for the MDR-1 gene.) It was mainly the vet tech that I dealt with, but I felt like I had to educate her about it. Riley received Sentinel. They also tried to push a flea/tick pill on us and sent us home with Simparica. Well, I took the time to read the packaging and the next morning I was calling the vet because it specifically says "not for use on puppies under 6 months of age" and something to the effect of severe neurological damage. Needless to say I didn't use it and returned it and have been in a bit of limbo since. The Sentinel protects against fleas, but not ticks (I was curious as to why they tried to push two flea treatments on him when he didn't even have fleas.) Anyway, I digress. I would like to protect him against future fleas/ticks, but I want to do it safely. He's going to be my hiking buddy and he doesn't need any nasty little hitchhikers. Have there been any advancements in collie safe medication? It's been about 15 years since I've owned a collie. Thanks!