Unless given a command to jump, a dog should never be allowed to jump on humans. A dog that jumps on humans of its own free will is a dog that does not respect the person it is jumping on. Even those cute little toy dogs should not be allowed to jump on people. While you may think it is cute, it is not cute to everyone else. Not only is it annoying to most people to have someone else's dog jump on them, it can also be dangerous. A jumping dog can knock people over, muddy their clothes, put runners in nylons and scratch the skin.
When your dog has all four paws on the floor, give him attention and praise. If he jumps up at any point, freeze with your arms folded on your chest until he calms down. Instruct guests and all members of your household to consistently ignore jumping. If you have visitors who ignore the no-jumping rules, keep your dog on leash during the visit and gently remove him if he jumps. For anything your dog gets in life, whether it's your attention or a meal, only give the reward when all four paws are on the floor. Jumping up should end all attention and rewards, while remaining fixed on the ground garners all the pleasurable reinforcement a dog desires — treats, petting, play.
You shouldn’t stop this type of jumping. You need to diagnose your dog's issue and remedy that. If your dog is just stressed being in a new situation, you should calmly get them off of you, offer them a treat to calm them down, and have them sit politely beside you until their stress level has subsided (or take them somewhere else so that they can calm down if it is taking a while for them to calm down.) But most of all, please do not just ignore this behavior change.
To a dog, space and balance are very important. If you take a step backwards or lean out of a jumping dog’s way, it will continue to jump. To a dog, it is overtaking your space, which only pack leaders are allowed to do. When a dog jumps, step into the dog. Picture a sphere around you and are not going to allow anyone or anything to come into your space. When the dog jumps, step into it sideways with your body, shoulder towards the dog. Don't face the dog head-on (you may not have time to turn so don’t worry about it if this is the case). You are not trying to knock the dog down, although this may happen. Don’t be alarmed if you do knock the dog over. Although you don’t want to abuse the dog by knocking it around, this may actually go a long way toward breaking it of the jumping habit as it will create a negative experience. Dogs are incredibly physical creatures and can withstand a lot of physicality without any harm. The odds of inflicting any serious injury are miniscule. You are simply calmly filling up your space with your body, and in return, setting the dog off-balance, which is an uncomfortable feeling for a dog. Lean slightly forward, not backward. Never lean backward, as you will be giving the dog that space. Casually and calmly, keep filling your space, not allowing room for the dog to come in. Remember, your goal is not to knock the dog down, it's just to retain your space.
If a dog is stressed or afraid, their demeanor and typical behaviors will change. If you see this in your dog (or really any dog you know) you should step back and check on your dog. Are they hurt? Did a new dog come around they don’t know? Has the weather changed? Is it hot outside? When was the last time they had a chance to go outside to pee or poop?
1. Do not let your dog make a big deal out of your arrival home. In fact, as the alpha leader of your family's "pack", you shouldn't even greet him or her for at least 15 minutes. If your dog jumps around and pesters you before that, squirt him with water pistol or shake a can filled with pebbles. This will startle him, and if done on a regular basis, calm him whenever you get home. He won't make such a big deal of your arrival, and thus learn that he can greet you without jumping. Follow the same technique for any visitors to your home. Do not introduce the dog to your visitors until after 15 minutes or longer.
By playing some simple games like fetch with your dog, you can kill 2 birds with one stone. First is that the actual playing of the game will surely tire them out so much that they won’t have the energy to jump the fence. Second is that you are associating the fun of the game with the yard. If they have fond memories of the yard they will be less likely to try and get out.
Dogs like and need consistency, so if you are not allowing your dog to jump on you, everyone in the family and everyone who greets the dog must do the same. You, as an owner, must make sure this happens. It will only confuse a dog if you allow them to jump on some people who say they do not mind, and tell him not to jump on others. Once you decide you do not wish your dog to jump on people you must apply this to everyone at all times unless you give the dog a command to jump. A dog should never jump on a human of its own free will.