How to stop a dog from being territorial over food with other dogs?

Resource guarding aggression, otherwise known as possession aggression, presents when a dog becomes territorial over possessions they deem to be exclusively theirs, such as their food, treats, toys, and bed. They fear losing their favorite possessions and will monitor from a distance and rush aggressively if another dog, pet, or human approaches their belongings. To manage resource guarding aggression, simply pick up your dog's toys, food bowls, and other possessions when your dog is not using them. This will create an “out of sight, out of mind” situation. Alleviate fear aggression by slowly socializing your dog, which will help them understand that other dogs, pets, and humans don’t always mean harm. Dogs are naturally territorial and protective creatures, but their behavior when feeling threatened should never rise to the level of aggression.

If your dog shows guarding behaviours, leave them well alone when they are enjoying food or playing with toys by themselves. To prevent resource guarding, the best way is to teach them from the start that there is no need to worry about losing anything they find valuable. This is a very important lesson and means they can always relax and enjoy the things they love without having to worry. How to train your dog not to guard their food bowl: Prepare some tasty treats for your dog, gently and quietly drop the extra treats on the ground near your dog as they’re finishing their dinner then walk away. Your dog needs to understand that they can enjoy these bonus treats without any pressure. Through repeating this and always moving away afterwards, your dog will learn to look forward to you approaching them while they’re eating. They will know that there is no risk of you taking anything away, and that you are actually bringing something nice. Always swap the dog's item for something else, being consistent and always swapping items will help dogs learn to share without being worried. If you need to take something from your dog, swap it for something else that your dog considers to be equally or even more valuable. You could drop several treats on the ground near your dog, so they have to leave the item to go and eat them. Then you can calmly pick up the item while they’re enjoying themselves.