[anonymously]

I think you worry too much 🙂
I use Sentinel, no problems noted. How do you know your dog doesn’t like it?

PS: I have used Heartgard in the past (without issues) but I had a dog that was in the herding breed family, so I switched.
I have used Spectrum products (Intercepter) too, but to tell the truth, I am happier using less chemicals whenever possible.