[Ellie May]

That i really the only reason most say not to give it to Yorkies. They have a high reaction rate. I suppose that's subjective though. Maybe it isn't as high as some other breeds, but it is higher than larger dogs. Sometimes lepto is so bad in an area that the vaccine needs to be considered (although some will disagree). When given though, it should be a single, not in a combo.

Sentinel is just Interceptor with Program. It is a good drug. The Program (for fleas) just makes it so they can't reproduce though. It doesn't kill them.