If he is stopping what he is doing and going over to the pad to pee and just missing, then there is nothing I would do but praise him. He is doing his best to go on the pad, and doesn't have the ability to know that his back end is off the edge. Maybe get bigger pads, but don't scold him when he goes to the right place but misses, since that might give him the idea that going to his pad to pee is a bad thing.
If he is only 4 months, he is not through teething yet. Most don't start to lose their baby teeth (front incisors) until around 5 months of age, and they lose all of their baby teeth and get their adult teeth by the time they are 7 months. He needs to chew, get him something to chew on besides your hands/toes. Tell him "ouch" when he does it and pull away, then provide him with an alternative. If that doesn't work, a squirt bottle filled with plain water works wonders (that shoots in a stream, not a mist), and just say "no" at the instant you are spraying him.
__________________ Life is merrier with a Yorkshire Terrier! Jezebel  & Chuy ... RIP: Barkley  Loosie & Sassy  |