Dogs, like humans can be trained at any stage of life, you just have to deal with them where they are not where you are. Young dogs have little attention spans and lots of energy, old dogs have long attention spans but not a lot of energy; use these characteristics to make your training fun for both of you.
The, so far, best ways to train animals are called lure and cue or 'clicker' training. Lure relies on an animal to follow a potential treat to be moved to a specific position, then the animal is cued ('good dog' and the treat is given). Clicker training is tougher but the pair (trainer, trainee) can create much much more complex trained behaviors.
With clicker training a series of goals is prepared by the trainer and each will lead to the next in 'shaping' the behavior wanted. The animal is first taught that the clicker (or whistle or snap or ...) signals that a treat is forthcoming. In the beginning it must be delivered every time. After a number of times (trainers choice), the treats come in random groups: 1 time 1 treat, next time 3 treats, next time 2 treats, and so on. The period of time used is directly related to the age of the animal, young keep it short 5-10 mins at most, old, up to 20 mins per session (usually 1 session per day.)
After the animal starts to catch on that cue (click, whistle, snap) means "treats", the trainer will try a few "no-shows" - when they receive the cue, animal does the animal instantly look for the treats? If so you can now move on to the next stage, the first part of the behavior. If looking to train an animal to fetch, once the cue = treats you reward positive behavior i.e. watch for the animal to move towards the item that the trainer wants delivered. Let the animal wander a bit and every time they head that direction - cue:treat. Always work from positive, that is, don't push them, let them figure it as they go.
After the animal is headed towards the thing to be retrieved over and over, stop cuing and treating just for going to it. Now you are looking for them to touch it. Generally they will attempt the old behavior (walking to it) and will randomly hit it; cue: BIG treat. Now the animal gets confused but most times retries whatever they just did: cue-treat! The animal now tries the new behavior over and over. Remember to keep the sessions short, and reduce the treat level when you are consistently getting the wanted behavior.
Now move to the next goal, here getting their nose near the object. Make sure to no longer cue-treat for touching the object, you are now cue-treating for touching with the nose. Rinse and repeat till you get them almost pushing it around. Now try for putting open mouth on it.
This set of cue-treat works with ANY animal with the right treat. Humans, dogs, cats, chickens, anything - you just have to deal with the limitations of the animal and your own limitations.
As to speed of learning, old animals (people, dogs, cats...) have a slower time learning because they have more connections already there in their head and it takes a while for new things to get settled in. Young animals have less connections and less to change in their heads so 'learning' is faster. ALL animals (non-brain damaged) can learn, you just have to be a friend, not a commander. Note this has worked for dogs 3 months old, 3 years old, 17 years old. It has worked with Orcas, Dolphins, cats, chickens..... Every animal that can learn can do so all it's life.
There is no yelling, no shoving the animal around, no punishment - positive works and works best. Unless there is harm about to come to a human otherwise, use no other method: you waste your time and the dogs.
Yes, you can teach your dog to attack.
To Bark on command and attack, (if its a guard dog like a German Shepard)
You can teach it that in the battle frontier in HeartGold and SoulSilver OR breed it Sky Attack.
You need to teach your dog that you are the dominate one not him. When your dog goes to attack or does anything else that is bad grab him by the scruff of the neck (the loose fleshy part) and force him to the ground (Make sure you don't hurt him though), keep him pinned down till he submits to you. The signs of submitting are looking away, baring the neck and baring the belly to you
'stay' is usually the second trick to teach a dog. first you teach your dog all the tricks needed if something where to happen. Just pretend your dog sees your neighbor walking another dog or maybe even a cat and your dog gets loose from the leash to attack your neighbors pet and right after it breaks free from the leash you yell "stay" or "sit" or even "lay down" you just saved your dogs life and your neighbors pets life. So its better if you teach your dog all the needed tricks and then after he knows those then you can get to the fun ones like shaking hands, jumping through a hoop, or even jumping rope. So please please please teach your dog the needed tricks first.
An attack dog is a dog bred, trained or used for the purpose of attacking a target.
"Teach your dog not to bark," he screamed.To teach is to give the gift of knowledge. Not everyone has the ability to teach.
Watch it my dog will attack
A dog whistle may not reliably stop a dog attack as its effectiveness can vary depending on the individual dog and the situation. It is always best to seek professional help in case of a dog attack.
Dog teach children resposibility
you can send your German Shepard to police friend if you have a friend on the force but make sure its legal with the law by checking with them. also toughen your dog up by getting them healthy. growl at your dog and teach them how to hunt. point at something you don't like and say attack.
Responsibility.