Here are some suggestions. My big dog is now 10 years old and 80 plus pounds, and this worked well for him. He is very well behaved. This is long, but it works!
1) Have a word for urinating/defecating that is short and that the dog can remember. The word we use is "outside". Sounds better than pee-pee or poo-poo, and it works just as well. Play with the puppy in the yard, and as soon as he starts urinating or defecating, say your word for that REPEATEDLY, and PRAISE HIM. Have a treat handy and give him that too. Let him know he did well to use it in the appropriate place. As he gets used to this, u can take him to a designated out of the way place, say the word, and he will go there so nobody will step in it. He just has to get used to it, and u have to be consistent with the word. DON'T spank him or bury his nose in a mess in the house UNLESS u see him do it. He won't understand punishment 15 minutes after the fact.
2) Get a big kennel that the dog can get in even as an adult. Put some cedar bedding in there for him to rest on. At night, put him in there when u r ready for bed and just after u took him outdoors to do his business. He WILL NOT soil his living space. In the morning, quickly take him outdoors while saying the word like I mentioned in #1 (outside), and he will do his business. Heartily praise him for that. He will be trained in less than a week. The big kennels are also great if u have company, a housekeeper, etc. that is scared of a big dog or who he is unfamiliar with. My dog's kennel has come into good use many times like this and also with transporting him to different places. He will grow to like it and probably even sleep in it.
3) As far as jumping on u, u need to nip that in the bud IMMEDIATELY. Try not to hit the dog with an open hand. Instead, try to always have something like a rolled up newspaper, or a stick, or etc. Scold him and teach him the word NO. The biting is not as bad as that is the puppy in him, and it should get better. Chew toys are the way to go, just make sure u have plenty. If u catch him the act of chewing on something he shouldn't, pull up on the loose skin in what would be his groin. He will stop immediately.
4) A shock collar is also a good training tool. They are NOT cruel, and if used to reinforce discipline and commands, they are a great tool. Don't let the dog see u pushing the shock button. He needs to associate the unpleasant sensation of the shock with bad behavior, not u. I found the shock collar especially useful when my dog kept wanting to go across the street. I would rather shock him and teach him than to have him run over.
5) A German Shepherd's natural instict is not to "fetch", so unlike a Labrador or other retriever, this is not innate. U can teach it that, however, but it will take time.
6) U did not mention if this dog is a male or not. I'm guessing it might be. If it is, u really need to let it know that u r the boss. This is especially hard with an Alpha Male. Here are some tips to remember. If the dog is laying in the floor in your path, NEVER step over or walk around him. ALWAYS make him move. NEVER let your dog go outside or walk ahead of u. Going second is a sign of submission. These next 2 might make u laugh, but they work! GROWL at your dog. Get right in his face and GROWL at him. Do not do it in jest or when u r playing. Bite him on the muzzle. Not a hard clamp down bite, but a little nip. Just enough so he feels it. The dominant "dog" (you) nips at the subordinates in this same manner. You have to speak in his language, so don't be afraid to GROWL at him and Bite him on the muzzle.
Good luck with your dog. Big dogs are the best and if controlled and well mannered, they are great and loyal friends.
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It's far better to be LUCKY than good.
