Everyone gets a little riled up when they feel threatened, and dogs are no exception. “Aggression serves a purpose for dogs,” says Katherine Miller, PhD, director of anti-cruelty behavior research for the ASPCA. “Dogs respond to real or perceived threats to their body, territory, or resources such as food or toys.” But if every passing animal or approaching stranger sends your dog into a fit of barking, growling, and snapping, some behavior therapy may be in order.

If your dog is still a puppy, you’re in luck. According to Miller, socializing a dog while it’s young is the best way to discourage aggressive behavior as an adult. Expose your pet to different types of people and places so they don’t react to them as a threat later on.

If they are past their puppy prime, a little retraining might be the best way to mellow out your pooch. One key to managing aggressive outbursts is to see them coming. “People say a dog didn’t give any warning, but usually there is one — it’s just unrecognized,” Miller says.

Signs of Dog Aggression

Watch for subtle changes in your pet’s demeanor, such as sudden stillness, looking out of the corner of their eye instead of directly at something, lowering their head, or hunkering down. Quickly divert your dog’s attention when any of these things happens — warning signs often occur a split second before a dog’s behavior escalates.

You can also head off aggression at the pass by respecting what your dog’s body language is telling you. “Don’t impose your will on the dog,” Miller says. Pushing your pup to play nice with a small child or another animal, even as they are pulling away, is a recipe for disaster.

When a normally placid dog becomes aggressive, visit a vet to rule out medical causes for the sudden change. If your dog is still fighting mad after following these steps, Miller says to seek help from a certified dog trainer or behaviorist.

Expert Tip

“Keep treats on hand during walks and offer one up before your dog lunges at the neighbor’s pooch. Or throw something tasty into his bowl if your dog growls when you get close while he’s eating.” — Katherine Miller, PhD