You are going to have to have absolute control over Pedro. When you say sit, he sits. When you say come, he comes. When you say leave it, he leaves it.
Even with all his training, the cats may not like the dogs and can cause the problems.
I have 3 chis and 2 cats. One chi absolutly loves the cats, the other 2 chis cautiously respect the cats. One cat loves the chis and the other cat tolerates the chi that loves the cats for short periods of time, but doesn't really want to be bothered and has no problem letting the chi know it.
I never go out and leave them all together, the cats get shut in my room. Even when I'm home I watch them when the cats are around.
You will probably be able to train your chi to be tolerant with the cats, it's the cats that may be the problem if they've never been around dogs.
Start by making the chi sit and stay when the cats are around.
Sandy, Koke and Lelaska's Mom