Experienced and professional animal trainer provide their insights in answering this question :
A. If puppy was too early separated from bith and siblings it can have problems with biting to strong. You should not let him allow to do this. show him that it hurts you, say firmly “no” and stop playing with him if he will bite you. Give him a toy that he will be allowed to bite and chew. If it won’t help see a behaviourist.

How to Identify Common Pet Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced pet care professionals :

Instead of giving your puppy time-outs for hard biting, start to give him time-outs every time you feel his teeth touch your skin. The instant you feel your puppy`s teeth touch you, give a high-pitched yelp. Then immediately walk away from him. Ignore him for 30 to 60 seconds.
The good news: in the vast majority of cases, puppy biting and mouthing is EXTREMELY normal, for several reasons: Puppies explore the world with their mouths. They go through an uncomfortable teething process that lasts for 2-3 months.
They`re Overstimulated

For a good reason, many like to call their German Shepherd puppies “land sharks.” Often, the nipping is a manifestation of a dog getting overstimulated and losing control of his bite force. Sometimes, German Shepherd puppies will get more and more nippy when they are cranky and in need of a nap.

A medical professional may treat any puncture wounds or lacerations, and in some cases, you may need a rabies shot. The hospital or doctor`s office should create a record of your injuries, which may be helpful if you decide to pursue a claim against the dog`s owner.
Use firm commands

Use firm commands when required to make your puppy stop biting. 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 tooth at your hand. You also can yelp or say “ow” in a loud, high-pitched tone.

When playtime is over, give her a potty break and then put her up for a rest. When she is loose and attacking your clothes and legs, stop moving and ask her for another behavior that you will reward. If this doesn`t work, calmly put her in her crate with a small treat for a puppy timeout.
For a dog who is acting out of fear or frustration (for example, a dog who is barking and lunging on leash), using the word `no` to stop the behavior without helping to alleviate their fear or frustration will often lead to an escalation in behavior, such as growling, air snapping, or biting.
In most cases, a playful dog will have a relaxed body and face. His muzzle might look wrinkled, but you won`t see a lot of tension in his facial muscles. Playful mouthing is usually less painful than more serious, aggressive biting. Most of the time, an aggressive dog`s body will look stiff.
Stand ahead. If your German Shepherd is in front of you when you meet other people and pets, he will think it is his job to protect you. However, if you are in front, he will relax and believe it is your job. This will prevent initial aggression when strangers approach and reinforces you as his leader.
German Shepherd bites can be around 238 pounds per square inch (psi) or more, which makes their bites stronger than a Pit Bull and more similar to that of a wolfdog or much larger breeds of dogs.
clean the bite thoroughly – if the wound is very dirty, some of the affected area may need to be removed to reduce the risk of infection. close the wound with stitches, sticky strips or special glue, or leave it open to heal. give you antibiotics to stop the wound becoming infected.
The most important thing to remember is that for the vast majority of puppies, mouthing or play biting is a phase that they will typically grow out of once they reach between three and five months of age.
For dogs under 6 months of age, much hyper and aggressive behavior is simply puppy play. But that doesn`t mean that you should just green light it and allow it to continue. You must teach your puppy boundaries and the earlier you teach them the better.
Does Spraying a Dog or Cat With Water Work? Nope, training your dog by spraying it with water does not work. When working with dog training clients, trainers have witnessed some who spray their puppies for mouthing, yet their arms are covered in scratches. Spraying the dog with water was not helping.
“The bites are not meant to hurt you, but rather to indicate the dog wants a play session, not a cuddle fest,” she adds. This is especially true for puppies and young dogs, who want to do nothing but play most of the day, she says. You may find this happens when you want to calmly pet your dog.
Statistics show that Pit Bulls are the type of dog breed that bite humans the most, with Rottweilers and German Shepherds being the second and third most likely to bite.
While you may think your touch is therapeutic, your dog may therefore not be in the right state of mind for such contact. Therefore, he may bite because he is too alert or defensive—or simply because he is bothered by your touch.
When puppies play with other puppies or explore their environment, they do so with their mouths. It is common for puppies to bite or “mouth” hands and clothes during play or when looking for attention. As annoying and sometimes painful as this behavior may be, it is normal and an important developmental behavior.
Some reasons dogs don`t come when called include distraction, confusion, or fear. Gradual training and positivity are ways to help build a reliable recall so your dog will come when called.
This aggressiveness is part of their hormonal progression but worsens through poor training, inappropriate socialization, and lack of guidance. Ensure the basics of socialization occur by the time your GSD is 14 weeks old.
From 3 to 9 Months

GSDs excel at obedience, so begin teaching your puppy basic commands like sit, down, and stay, as well as loose-leash walking, from an early age.

Enriching your dog`s life with puzzles, treats, chew toys, new experiences, and new training skills will also help to keep them calm, better behaved, and turn them into well rounded pets that don`t get over stimulated over every new thing they see or smell.
Even if your GSD doesn`t have epilepsy or another condition linked with aggression, their new-found behavior problem may be a sign that they`re in pain. Many dogs will behave aggressively if they`re in pain, and your dog may need medical attention and pain relief.
The puppy biting seemed to be getting a little better. But now it`s getting worse again! Most likely your puppy is teething. The baby teeth are getting ready to fall out and the adult teeth are starting to come in.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Q. How do we stop our 2 month old Shepard/retriever mix from biting?
ANSWER : A. If puppy was too early separated from bith and siblings it can have problems with biting to strong. You should not let him allow to do this. show him that it hurts you, say firmly “no” and stop playing with him if he will bite you. Give him a toy that he will be allowed to bite and chew. If it won’t help see a behaviourist.

Q. I have a 8 month old Lab. He gets excited and likes to get mouthy and puts the persons hands in his mouth. Doesn’t bite hard. How can we stop this?
ANSWER : A. Bite inhibition is a great way to stop mouthiness that occurs often with teenaged dogs. There are several training techniques that can be done to help teach your dog how to play nicely! One is to teach a “Leave-it” command. Begin by holding a treat in your hand and asking your dog to “leave it”. If he attempts to chew or bite, a high-pitched YELP! will help. Once he backs away or ignores the treat, ask him to “take it” and offer it to him. Another useful way to teach bite inhibition is through the use of a tug toy. Again, the “take it” and “leave it” commands are used. During a tug session, ask your dog to “leave it” or “drop” and exchange with a treat. If he lets go of the toy, reward him! One final option is also “airplaning” treats. This method involves having your dog sit and then slowly lowering a treat toward him. If he goes for the treat, back away and start over. Once he can sit calmly and not chew on you, reward with the treat! All of these techniques are great for helping teach dogs bite inhibition. 🙂

Read Full Q/A … : Leerburg

Q. 2 month old Bulldog. While playing gets TOO rough:gripping hand REALLY tight/growling/shaking to the point of drawing blood. Aggresive?Normal?HELP!!
ANSWER : A. For the most part, this sounds pretty normal to me. English Bulldogs can be like this. What you can do is teach him bite inhibition. He needs to know that biting gets him nothing. Each and every time he nips, even gently, you immediately yelp like a puppy would, stand up, cross your arms, and ignore your puppy. Once he is ignoring you, go back to calmly playing with him WITH A TOY. Remember to always use a toy when playing with/petting/interacting with puppies. They will be teething very soon, and they don’t understand that biting you is inappropriate, so using a toy to redirect their attention is important. He needs SOMETHING to bite, or else he will choose your hand. Give him more options.

Another thing you can do is have a toy that YOU OWN. This can be a soft braided rope toy or something of the like. Dot not allow your dog to have this toy whenever he wants. This toy disappears when you are done playing with him with it, and reappears when you want to play. Never allow him to “win” games with this toy. Eventually, the toy will hold so much meaning, when he sees it, he will be instantly interested in the toy instead of your hands.

It also helps to have two bags of toys. Bag#1 is full of chew toys/rope toys/soft toys/etc. It comes out for one week, and then disappears and out comes Bag#2. Bag#2 has the same types of toys in it. This will keep the toys feeling like “new” to your pup and make him less likely to chew on you during play!

Q. How do I get my 10 wk old puppy to stop biting? He only bites me and my fiancé but licks everyone else. Tried bitter bite spray but he just barks.
ANSWER : A. When greeting your puppy, you should present an appropriate alternative for him to chew on. This can come in the form of toys. It’s normal for this age for puppies to be bitey. When you greet him, immediately offer a toy for him to chew on and calmly pet him. If he bites you instead, there are a few things you can try. You can yelp loudly startling him just as a sibling would do. You can freeze not jerking your hand away since that can likely become a game to him and you can also keep him secured in a play yard where if he bites, you can simply remove yourself from him so he learns all a attention goes away when he bites. Only give attention when he is calm.

Read Full Q/A … : Leerburg

Q. How can you help stop your dog from ‘play-biting’ and ‘mouthing’ when I’m trying to touch him in any way?
ANSWER : A. Is it still a puppy? It is a lot easier to stop a puppy from doing it than an older dog that has been doing it for sometime.
Try this…..as soon as it play bites or jumps up at you. Stop playing immediately stand up and turn your back on the dog, ignore the dog, even carry on with other tasks, or talk to someone else. Once dog stops then try stroking it again, as soon as it play bites again, stop and keep repeating until he doesn’t do it anymore. For it to be successful EVERYONE needs to do it EVERYTIME. Even with a young puppy it may take a couple of weeks. But it will take longer if you don’t persevere.

Q. I recently added a new 2 month old female kitten to my house and my male 5 month the old kitten has turned aggressive and chases the kitten down..
ANSWER : A. It is possible it could be play behavior but without seeing it in person, hard to say. Is the male kitten neutered? You may want to consider doing so. Also, try re-introducing the kittens slowly by creating a safe space for the new kitten behind a closed door in a room. Keep her there for at least a week so she is protected but your male is still able to smell her. After a week or 2, you can then graduate to using a baby gate so they can then not only smell each other but safely see each other as well. If that is going okay, after another few days you can bring the gate down. Also, be sure to have feeding bowls in separate locations and at least 2 litter boxes.

Read Full Q/A … : Ragdoll Cats

Q. I have a pup that haven’t been 2 1.2 months old eating good for week. I have worm her once a week since she been 2 weeks old.
ANSWER : A. It is recommended to worm a puppy every 2-3 weeks initially and then every 2-3 months so you don’t have to give her worming medications every week any longer.

Q. My puppy is 15 weeks old and is biting me. I can’t seem to stop her. What should I do?
ANSWER : A. Biting and nibbling is very common in puppies, as like infants, they tend to explore their environment with their mouths. As a puppy hits about 5-7 months of age, her adult teeth will also begin to come in, making his need to chew even higher! Providing plenty of distracting chews as well as teaching some bite inhibition can help to save your fingers! Chew toys such as thick canvas toys, toys that can be cooled in the fridge to soothe sore gums and toys that treats can be hidden in make for a great chew experience. If your fingers and hands are the target, letting out a loud “YELP!” and walking away can also teach your puppy that you do not enjoy her nibble sessions. Another way to teach bite control is through “air-planing” treats which involves slowly moving the treat down to your dog’s nose. If she jumps or gets too excited, remove the treat and start again. If she stays calm and doesn’t lunge, award her the treat. This can help teach her patience and control when playing with people!