How to teach a dog to not be aggressive to other dogs?

Teach them a Watch Me exercise, do this randomly throughout the day, start where there are no distractions, and your dog isn’t doing something else. Say their name enthusiastically and when they look at you reward them with a high value treat. Once you can do this at home, you can progress to the garden where there are more distractions from sights, sounds, and smells. Distract them when meeting other dogs, start off a long distance from them – beyond the point where your dog would usually react. All you want your dog to do is look at you, and you will reward this. Always use high value treats to reward them for paying attention to you and not the other dog. Practice is key, remember that patience is very important when training any dog and you shouldn’t expect instant results. Practice can take some time and results can vary depending on your dog’s personality and breed so be prepared to allocate sufficient time and effort for training sessions. Give play opportunities, make sure your dog still gets a chance to play and interact with their chosen doggie friends, set up play dates or dog walks with a chance for off-lead play regularly with your dog’s best friends.

Training your dog not to attack other dogs might sound relatively straightforward, but it can actually be extremely challenging. Rectifying aggressive behavior in puppies will be quicker and easier than changing the habits of older dogs, but it's absolutely vital if you want to avoid serious injury to your own dog and others. Consistency is key with this type of training, so you need to be prepared to be patient and put in the hours. Counter conditioning teaches your dog that staying calm around other dogs earns them a tasty reward. Once you've reached the threshold distance and your pup sees the other dog, start feeding them treats and giving praise. If they react calmly, continue lavishing them with treats and praise so they know they're on the right track. You may need to go on dozens of walks or host several training sessions before the concept sinks in. Never punish your dog by yelling at or hitting them; this will only perpetuate the behavior and make them fearful of you. Eventually, your dog will associate seeing another dog at the threshold distance with getting a treat. Over time, once your pup is able to walk calmly past another dog, you may want to add another dog to the mix.