I've been using Trifexis for my two adult dogs since it came out, and never had any problem. One time Jax kept picking the cheese off of the pill and dropping the pill, but he usually eats it right up. I think the trick is to not let them realize there's a pill in there in the first place, so they eat it without thinking about it.
Make sure you give the pill with a meal. That's supposed to prevent vomiting. |