Play, Aggression, And Predation
Many dog owners are nervous when their dogs are playing. It can be difficult to determine what is and isn’t play without a trained eye. Play behaviors imitate hunting behaviors: stare, stalk, chase, grab, shake, kill, and dissect. We have selected and bred these traits to work for us (point, track, herd, retrieve) and see modified versions of these behaviors in both dog/dog and dog/human play (fetch, tug, tear up your toy, wrestle, chase). A certain level of predation is not only normal, it’s expected… we bred for it. There is a lot of overlap in the topography of play behaviors, aggressive behaviors, and predatory behaviors.
Predation is often confused with aggression. Aggressive behavior is often an escalation of communication meant to resolve conflict, provide defense, or protect resources. You may see some aggressive behavior if playmates have poor social skills and do not take pauses to check in with one another, switch rolls frequently (dog on top becomes dog on bottom, chaser becomes the chased), or listen to their play partner when the partner says “hey, that was too much”. Aggressive responses usually require only as much energy as is absolutely essential to get the job done. While aggressive behavior in play is NOT okay, it is a predictable response when too many dogs are playing together or dogs are behaving rudely towards other dogs. Predatory behavior in play is also NOT okay, and it’s (thankfully) a very rare occurrence.
Unlike aggression, which serves to resolve conflict, predatory behavior (stare, stalk, chase, grab, shake, kill, dissect) serves to provide food for an animal. While play behavior, predatory behavior, and aggressive behavior may look similar, it’s important to keep in mind that these behaviors serve different functions. Context and purpose are critical to understanding and potentially modifying or preventing the behavior. The purpose of aggressive behavior is not related to the acquisition of food. Predations very specific purpose of food acquisition more often ends with injury or death. Food has to be caught and killed.
“Predatory Drift” is a term that was coined either by Ian Dunbar (who mentioned the phenomenon in passing during a lecture) or Jean Donaldson (who first published the term) to describe a dangerous occurrence when seemingly without warning a large dog who is playing with a small dog will switch from appropriate play behavior to predatory behavior. This may result in severe injury or death to the victim dog and is the reason safer dog parks and daycares have separate areas for small and large dogs. The term was likely influenced by the term Instinctive Drift which has since been debunked.*
While “predatory drift” is not a scientific term and is not well studied**, it is a term used among many behavior professionals to describe this terrifying phenomenon when play quickly turns deadly. In the classic “predatory drift” scenario, the attacker is a large dog and the victim a small dog. While there is often no perceivable trigger***, in a classic case of “predatory drift” the small dog will trigger predatory behavior in the large dog by doing things that prey often does: squealing, giving submissive body language signals or by running away from the other dog. To further complicate matters, the little dog may even resemble a small critter to an under socialized dog. After all, a Great Dane and a Chihuahua are the same species but they don’t look much alike!
It’s clear that the motivation for play, aggression, and predation is drastically different, as are the consequences. The confusion lies here: The motor patterns (the topography of the behavior) are so similar that it can be hard to tell the difference at first glance. The differences are especially subtle to an untrained eye. I often hear clients say “everything was fine and then OUT OF THE BLUE the dog attacked or OUT OF THE BLUE my big dog picked up the little dog and was shaking it.” But here’s the rub: Behavior always happens for a reason, and while some behavior professionals feel that classic predatory drift is a weird “tick” that we don’t yet have the tools or knowledge to explain or a phenomenon where the brain switches from the play neurological circuits over to the predatory neurological circuits in an instant (which we do not have proof of), others feel that this is not a mysterious phenomenon, but a predictable one. Play preceding the attack, if viewed by a trained eye, may not be as appropriate as an owner thought. Canine communication can be both subtle and quick, and even professionals may need to play a video in slow motion to truly analyze what went on in any one interaction. To complicate matters, a lack of socialization or insufficient socialization means many dogs don’t understand that certain vocalizations or body language postures mean “that’s enough!” “let’s take a break” “please stop that” or “I don’t want to play”. Instead of taking an appropriate breather, their play partner takes play to the next level. They remain aroused, continue to overwhelm the other dog, and may even do harm. To add stress to an already scary occurrence, anecdotal evidence shows that once a dog has exhibited this behavior it tends to escalate. If your large dog picked up and shook a small dog at the park but didn’t do any harm, chances are next time that little dog will have puncture marks or end up dead. There is an operant explanation for this: the behavior is fun. Dopamine is released during each phase of the predatory sequence****. It’s addicting.
It is my understanding that most ethologists, neurobiologists, and applied behavior analysts agree that Predatory Drift is not an unexplained, mysterious phenomenon. I believe it is a predictable behavior elicited by a combination of poor canine social skills, high arousal, and a trigger that is predictable but hard for humans to perceive. The dangerous behavior that follows is heavily reinforced (fun! dopamine!) and likely to reoccur. Whether I am right and there is predictable stimuli and variables that elicit an attack or there is a “switch” we haven’t yet found that clicks the brain over from “play” to “predation” doesn’t matter much. There is only one solution:
Prevention. Prevention. Prevention.
If you are the owner of a large dog who, mid play, has attacked a small dog “out of the blue” your dog can no longer enter mixed sized dog parks or day cares. No large dog/small dog interactions are allowed. Your pup needs to play exclusively with buddies of his or her own size.
However, when looking at the “whys” and the “how can I prevent this?” there are a few additional things to consider.
If your dog just started a new medication, a paradoxical effect to the medication or disinhibition due to the medication may cause an unwanted change in behavior. Let your veterinarian know immediately.
Any sudden change in behavior warrants a trip to the vet for diagnostic testing. Dogs who are feeling unwell or are in pain can display aggression “out of the blue” with no perceivable triggering stimuli. Schedule a check up ASAP.
Lack of Play Skills and Adequate Socialization
Your dog may not play appropriately, even with dogs of a similar size. Learn more about dog body language and play. Is your dog playing appropriately with dogs of all sizes? Perhaps your pup is not comfortable or happy around other dogs. Perhaps your dog is pushy and doesn’t read other dog’s body language signals accurately. If your pup is stressed in canine social situations, you may have a dog that shouldn’t go to the park or to daycare. Many dogs are much happier playing with their people, and don’t need to interact with dogs to have a happy life. In fact, these canines are much happier not interacting with other canines! Maybe you have a humans-only canine! If you need help, there are many professionals who are happy to review video footage of your pup playing, or meet you at the park to assess your pup playing (with pups of similar sizes). Keep in Mind: A good behavior professional will NEVER put your dog in a dangerous situation (or ask you to) hoping that your dog will repeat an aggressive or predatory response. Professionals will only ever set you up for success with safety always in mind.
Training and Behavior Modification
Training: Perhaps there is a clear trigger (antecedent) to this behavior for your dog. Maybe you know what it is – maybe you don’t. It doesn’t matter. You can’t train your dog out of this. Don’t allow your large dog to play with small dogs. It only takes one slip up… stand your ground. Advocate for the safety of your dog and for others dogs. Don’t let someone else convince you that your large dog will play with their small dog just fine because “my small dog prefers playing with big dogs”. Nope. Never. Make sure that everyone who is responsible for your dogs care is clear about this as well. Repeat yourself ad nauseam. As the old saying goes, an ounce of prevention is worth a pound of cure and this is compounded by the truth that there is no cure for these dogs. The risk of training is not worth it. Imagine if your dog injures or kills another dog during training. There is no room for error. PREVENTION. PREVENTION. PREVENTION.
*We now know that poor training choices – like choosing a “reinforcer” that the animal does not find reinforcing – explain why this would happen. Instinctive Drift is not a real phenomenon. However, Breland and Bailey’s paper The Misbehavior of Organisms is still a great read.
**I’m not sure how this would be safely studied. It’s a rare event and is caught on camera even less frequently. After the fact descriptions are often incomplete, as this happens very quickly and often in the presence of owners who may not have a full understanding of canine body language.
***If further study were possible, this information may change. The term predatory drift specifically refers to this phenomenon when there is no circumstance or stimuli that triggers one dog to move instantaneously from play to predatory behavior. Predatory drift does NOT refer to cases where there is a predictable, stimuli inducing aggressive response.
****Ken McCort Seminar on Arousal, 2016
Thanks to Ken McCort, Ruth Crisler, Greta Kaplan, Brian Burton, and Sarah Fraser for sharing their thoughts with me on the topic of Predatory Drift! I hope you’ll share your thoughts in the comments.