My dog is a talker. When he's with another dog, he constantly barks and growls as he races around the yard, so incredibly excited to run and play. For people who don't know Brodie, it can be off-putting the first time they see and hear his noisy behavior. But when you see his play bows and happy, waggy tail, you realize the growling is just part of the way he plays.

Dog growling is often associated with aggressiveness, but there are other reasons (like playing) that growling can be part of a dog's vocabulary.

Recently, a team of researchers from Eötvös Loránd University in Hungary conducted a study to see how well people could interpret dog growls. They made recordings of three types of growls from 18 dogs: when dogs were guarding their food, when they felt threatened by a stranger, and when they were playing tug-of-war with their owners.

The researchers played the recordings for 40 volunteers and asked them if they could differentiate between the growls. They were able to correctly classify the growls 63 percent of the time. Not surprisingly, dog owners were more successful than non-dog owners and women were more likely to correctly classify the growls than men.

Volunteers were more successful in recognizing when the growls were from playing dogs and had a more difficult time telling the difference between dogs that were threatened and dogs guarding their food. The study was published in the journal Royal Society Open Science.

Types of growls

two dogs play fighting Play growling is 'happy' growling, but sometimes it can escalate if energy levels get too high. (Photo: elbud/Shutterstock)

There are all sorts of growls, triggered by an array of canine emotions. San Francisco-area certified dog trainer Chad Culp of Thriving Canine breaks down growling into six types:

Play growling — This is "good" growling that dogs do when they're playing with each other or even with their owners during roughhousing games like tug-of-war. If it seems to be getting a little out of hand, give the dogs a timeout to let energy levels come down a little.

Pleasure growling — Some dogs will growl affectionately when they are being petted or as a request for attention. Some people think it's a threat, but it's a sign of happiness.

Threat growling — Often seen in dogs that are fearful, territorial or possessive, this growl tells a perceived threat to go away. The dog wants to increase the distance between itself and the threat.

Aggressive growling — The most dangerous, the growl comes from a dog that intends to do harm. It wants to decrease the distance between itself and the object of its aggression.

Frustration growling — A dog stuck behind a fence or on the end of a leash may growl when it sees another dog or something else it would like to be closer to. It's typically a combination of play growling and threat growling and the dog's general inability to deal with frustration.

Fight growling — When dogs are fighting or when raucous play has turned into a fight.

Don't stifle the growl

angry dog growling Don't correct your dog for growling; it's his way of communicating. (Photo: arrowsmith2/Shutterstock)

Dog trainers and behaviorists say that growling is a common reason people consult them to work with their pets. But it's never a good idea to train your dog to stop growling, says certified canine trainer and behaviorist Susie Aga, owner of Atlanta Dog Trainer.

"A lot of people correct their dogs for growling but it's a communication tool. They're letting you know their emotional state," she says. "If a dog growls and the owner says, 'shush,' it doesn't change the dog's mindset. It just changes its signals."

So instead of giving a warning sign that he doesn't want another dog coming near his food or a person getting closer, when trained not to growl the dog can "go from zero to a bite," Aga says.

"Growls are extremely important. Growling is a sign that some emotion has changed — sad or happy, aggressive or protective. It's the communication that tells you that something is different."

If you want your dog to stop growling, don't correct him. Instead, call him to you and put him in an obedience command, Aga says.

And if you're faced with a growling dog that is obviously not playing?

Aga says don't go forward. Take off any hats or glasses so the dog can see your eyes. Keep your arms folded. Turn sideways, so you're in a neutral position. Know where the dog is, but don’t make eye contact. Back away, but don't run. And don't turn your back, because a fearful, growling dog might bite you on the rear.

Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.