Sooner or later all dog owners will come to the realization that training their dog or puppy how to stop biting is important. It could prevent injuries – and the best time to start is when your dog is still a little puppy.
When puppies in a litter are playing with their brother and sister puppies, usually, they will nip at each other constantly, and naturally test their limits. When one of the puppies bites a bit too hard the other will bite back hard in return, not fun.
This is a good lesson for the puppy, he or she will now know the difference between gently nipping and biting. The puppy will be aware in the future about how hard it can bite. However, when a puppy is raised away from his litter, at home. He won’t get the same chance to learn it.
As a result, it will try nipping other family members and maybe even the cat. This is the point where you should start telling your puppy that biting is not ok, especially the cat, he was just minding his own business and a wild puppy ran over and bit his tail. Not ok!
Teaching a puppy at a young age to stop biting this way, will be less likely to bite as an adult dog

Useful tips
Quite frequently, the puppy is just trying to test its boundaries, and perhaps to establish dominance. As the owner, it’s your job to be the “alpha” here.
Let’s say your puppy is playing with you and, either inadvertently or intentionally bite you a bit too hard. You, the owner, should then exclaim a loud yeap in pain, it’s ok to exaggerate the sound and make it very loud, loud enough to shock your puppy. Not very “Alpha” I know but trust me it works, A loud “OUCH” will get the job done.
Your puppy should know it did something wrong at this point. Immediately stop playing with it, place the puppy in a crate, and ignore it for a little while.
Should it happen again next time you’re playing with your puppy repeat the process. Soon it will understand that you do not subscribe to biting.

Chew Toys
Alternatively, you can give your puppy a chew toy or like a dog bone to gnaw on if it’s trying to nip or bite you. Dogs find chewing to be a calming process throughout their life.
If the puppy is presented often enough with a chew toy it will start to realize that biting is only for toys and shouldn’t be done on humans or cats. The puppy will understand that humans are sensitive, that biting hurts. It is instincts but they still need some guidance.
Play Time
When going out to play with your puppy, it’ll be a good idea to let it play and interact with other dogs and puppies. This is in order to allow your puppy to expend its pent-up energy and generally would be less aggressive.
Exercise is always going to be crucial for your puppy throughout its life. More exercise equals more “release”.
A sign to see if your dog is getting insufficient exercise is if it barks incessantly, sprints around the house, or acts aggressively. Always make sure your puppy or dog gets enough exercise daily starting from a young age.
Never hit your puppy when it bites you. This could hurt the dog and can excite it even more and cause it to wanna bite you even harder. Always train your puppy with love and emotion. Physical punishment is only going to create an aggressive and scared dog in the future.
I would really recommend you giving the tips in this article a try. As long as you are isolating your puppy when it bites you, and avoid contact and communications with it for about an hour afterward. Over time it will understand that biting has never been the answer.