Dog training - All biting should be eliminated by the age of 15 weeks
However, if this is still presents a problem or if you have adopted a dog that's a little older than 15 weeks and is new in the home, then the following tips can help you get your dog to stop biting your hands and biting at your fingers:
1. The first item on your checklist must be to immediately discontinue playing all dog games that include roughhousing. I realize that part of the fun of having a new dog is playing games like tug-of-war and wrestling, but unfortunately, this technique doesn’t work for many dogs. So, if you're faced with an animal that is still not over his biting period, you have to stop these types of activities. By playing these games, you are giving him the notion that he is allowed to roughhouse with you at any time he wants. You have to be very careful because you don’t want your dog to be hostile towards strangers and young children.
2. While it's okay to allow some light biting, let me stress light biting, from very young puppies, when your dog is older than 15 weeks, all forms of biting should be completely discouraged. It doesn't matter if it's just a little nibble on your fingertips or hand that seems to be harmless, give your dog a firm command to stop biting that and immediately pull your arm away.
3. If need be, apply a type of “shock method” to get your dog to stop biting. Keep in mind that I am not talking about anything that is harmful to your dog. A spritz bottle of water fits the bill very well. Anything that you can quickly spray at his little body or head when he bits or nibble is enough to stop him from wanting to bite ever again. Most of the time, this method is all a pet owner will need in order to eliminate their dog's mouthing issue.
4. Lastly, use firm and disciplinary commands when it is needed. This goes for puppies of all ages. There is nothing wrong with quickly giving a loud and firm "No-Bite!" command if you feel a teeth at your hand. However, there are two things to keep in mind here: Do not scream so loud that it scares your dog, and second, don’t star at your dog's eyes for a long period of time because he will take this as a confrontation.