Don't punish your dog for growling at the puppy. Growling is normal dog communication, and he is letting the puppy (and you) know he's had enough. Instead of punishing this important communication, calmly separate them.
Introduce them away from home base
It's usually best to introduce your older dog to the puppy at a neutral location, not at your home. Doing so will help prevent any territoriality that your older dog may show.
No scolding, no yelling, and no physical punishment. Gently take hold of her collar, lead her to a quiet room away from the action, and leave her there with a bowl of water and a chew toy. Your visitor may expect you to punish your dog, even “alpha roll” her, if he's watched a certain television show.
If your dog is biting the puppy, causing injury, or acting inappropriately aggressive toward the puppy, you should seek professional help from a positive reinforcement behavior professional. Sometimes, it's difficult to know whether or not the older dog is behaving appropriately with the puppy.
It's normal for your older dog to feel a bit violated when you bring a new dog into the house, and sometimes puppies, with their lack of manners, can be a bit inconsiderate to their seniors. That being said, it's possible to find peace between your two dogs, especially if you start by introducing them correctly.
Some dogs don't tolerate puppies at all, and may have over-the-top reactions that could harm the puppy. It's important to keep a watchful eye on the interactions, and intervene when body language and communication escalate to an unsafe level.
It is 100 percent normal for your adult dog(s) not to love a puppy. It's OK for your adult dog not to want to be jumped on or be a chew toy for a new puppy. Dogs aren't programmed to take care of youngsters. Your dog may want to go away from the puppy or may growl or even snap to tell the puppy to go away.
It can take up to one month for an old dog and new dog to really settle in and accept each other's position in the pack. If you want a second dog, you need to be ready to commit to this process and not panic.
When you allow an adult to correct a puppy it should be done only when the puppy has done something directly to the adult. For example, if the puppy is running through the house do not allow the adult dog to make up its own rule that the puppy is not allowed to run.
Physical or verbal reprimands can potentially make the situation worse because your dog may see it as an escalation of aggressive behavior on your part. Try to place your dog in another area of the house, such as a bathroom or the laundry room (assuming he cannot get into garbage or cleaning products).
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.
Dog bites are not rare; these are common events that occur in normal family's lives and it is estimated that 15% of dog owners have been bitten by their own dog. Once a dog bites, he has shown his willingness to use biting as a behavioral strategy at least in that situation and therefore is more likely to bite.
If your adult dog seems unusually aggressive toward puppies, veteran dog trainer Robert Cabral says that may be because they've had a bad experience with puppies in the past…or might not have any experience with them at all. Your dog may be triggered by their fast movements and unpredictable behavior.
Dogs in the same household can become aggressive toward each other for a variety of different reasons. Aggression may be dominance-related, territorial, possessive, or caused by fear/anxiety. Some dogs have “alliance aggression”.
Introduce on neutral territory.
Each dog should be walked separately on a leash, and each walker should have a bag of high-value treats or food broken into small pieces. At first, walk the dogs at a distance where they can see each other but are not too provoked by each other's presence.
The amount of time each individual pet needs to adjust to their new homes will vary, but the 3-3-3 rule helps give an approximation of what new pet owners can expect. The 3-3-3 rule refers to the first 3 days, the first 3 weeks, and the first 3 months after bringing a shelter animal home.
Like humans, dogs have physical and emotional needs. They get jealous if they feel they are not getting enough attention because of a new family member or a new pup. This can also be made worse if your puppy is untrained!
But two dogs living together is also about them getting on well together. Be alert for encouraging signs that the older dog is accepting the younger. This could be the older one wagging his tail when the pup approaches, or engaging in a game of tug.
Dogs may growl during playtime to show their enthusiasm or excitement. If you observe that your dog is wagging its tail while growling, it's a good indication that they are enjoying themselves.
Older dogs may find it difficult to share their resources, space and attention - after all, they've had everything to themselves until now! They've had the freedom of the house to eat and sleep wherever they want - and it may not come naturally to share this with a new bouncy puppy who seems to get all the attention.
Dogs that are playing may roll on their backs or otherwise give their play partner the upper hand for a bit. But if you're seeing all pursuit, no give and take… if one dog is doing all the chasing and not letting the other get away—or body slamming—that's moving into aggressive territory.
You should NOT punish a dog for biting. This method may also teach the dog not to give a warning prior to the bite. It certainly doesn't do anything to minimize the dog's stressors.
Take steps to prevent your dog from biting again. In most cases, a dog bite can be easily prevented by taking the proper safety measures. If you are able to determine what triggered the bite, try to keep your dog from getting into the same situation. Work with your dog to adjust its reaction to the trigger.
Most dogs that bite do not need to be put down.
You should use modern no-harm training methods and take proper precautions when your dog is around others. However, if the attack leads to a criminal charge, the court may determine the dog is a danger to public safety and may require that they be euthanized.