Dog-Dog Aggression Between Housemates Part Two: Bites

Last week, I covered the scenario leading up to a devastating incident in which my younger dog, Trout, attacked my older dog, Layla, and the two dogs fought. While the fight was ended quickly with the fast actions of myself and my boyfriend, the injuries that the two dogs sustained took a bit longer to heal. This week, I want to talk about the story the injuries told me.

Where a dog bites another dog is very meaningful. Different bite locations tell us about the dog’s intentions during the fight – one reason why I always ask where one dog bit another when I’m working dog aggression cases. The severity of the bites is also very meaningful and gives a good idea of how safe the dog is to work with. Past history is a great indicator of future behavior, which means that knowing where and how hard Layla and Trout have bitten other dogs can tell us a lot about what they’re likely to do in the future.

After the fight, both dogs had injuries. Trout’s injuries initially appeared worse. She had a gash over her eye that was bleeding profusely and was eventually closed with two sutures, as well as punctures on her cheek and ear that were also bleeding but which didn’t require any medical care other than thorough cleaning. Since she’s a white dog, the blood from her wounds was starkly visible and very shocking. She fussed at her injuries, trying to paw at the gash above her eyebrow, so her paws quickly became red with blood too. She also had blood around her mouth from Layla.

Injuries to the face and ears such as those Trout received are the most typical injuries sustained in dog fights, and they can certainly be alarming at first. Ears and tongues especially tend to bleed alarmingly, and the wounds on ears often have trouble clotting as the dog shakes his or her head, reopening the wound and causing further damage (not to mention the crime-scene-like atmosphere that the splatter of blood such head shaking creates).

That said, injuries to the face tend to be the least concerning to professional dog behavior consultants. They’re the most common, as the skin there is thin and easily torn, and are also indicative that the dog(s) were not fighting with serious intent to harm but rather disagreeing. It’s the difference between a bar-room scuffle and a knife fight in an alley – there may be a broken nose or cracked knuckles in the bar room brawl, but no one’s actively trying to kill their combatant. Dogs who bite at other dogs’ faces or ears are angry, but not usually serious about causing damage.

Next up in the hierarchy of seriousness are bites to the sides of the neck, shoulders, or hips. These bites are a sign that the dog is taking the fight to the next level, but still is not yet intent on causing serious harm. Even more concerning are dogs who bite at the base of the skull, over the jugular, or on the other dog’s legs. These dogs are trying to disable or kill their opponent. The very most serious of dogs, who typically go for the underside of their opponent in an attempt to disembowel them, are intent not on disabling but on causing death, and dogs who injure in this way should never again be allowed in the presence of other dogs without extremely careful management such as the use of leashes and basket muzzles.

Layla’s injuries initially didn’t look too serious. She was missing tufts of fur and had extensive bruising over her chest and breastbone, and a deep gash on her right hind leg just above her knee. However, these bite wounds concerned me much more than Trout’s very visible and bloody battle scars. The wound in Layla’s back leg required the placement of a drain, and the entire wound took eight sutures to close. Layla was not able to bear much weight on that leg for close to 24 hours, and even today after the external wound has healed she still experiences some weakness and trembling in that leg after exertion, for which we’ve made an appointment with a veterinary rehabilitation specialist.

Bruising without punctures – a Level 2 bite.

So, what do the pattern of Layla’s injuries tell us? Trout began by biting me on the elbow as I attempted to block her attack, bruising but not puncturing the inner part of my arm. This sort of bite is considered a Level 2 bite out of 6 using Dr. Ian Dunbar’s bite scale, which starts with Level 1 bites (snapping without making contact) and ends at Level 6 bites (where the dog kills the victim or consumes flesh). Generally, euthanasia is recommended as the safest option for dogs who cause Level 4 or higher bites, which refers to dogs who bite deeply enough to puncture more than half the length of their canine tooth, and who may grab the victim and shake or tear flesh as they slash.

After launching herself over me, Trout then began biting at Layla’s chest and over her breastbone, again bruising (and removing tufts of fur), but not puncturing. During this time, she had decent bite inhibition, a term that refers to how strongly a dog bites down. Bite inhibition is one of the most accurate predictors of rehabilitation in dogs. A dog who snaps without making contact or who bites without puncturing skin is much less likely to cause serious damage in the future, while a dog who has hurt another dog badly enough to require medical attention is much more likely to cause that level of damage in the future.

The fact that Trout was biting at Layla’s chest and over her breastbone tells us that she was much more serious about “winning” the fight than was Layla, who was biting at Trout’s face in an attempt to back her off. However, initially Layla had worse bite inhibition, actually breaking skin on Trout rather than just bruising. This is something I know about Layla, and one of the main reasons I am so careful when introducing her to new dogs. While she’s never seriously hurt another dog, she’s punctured the skin on a face or ear on a handful of occasions.

The intensity of the fight likely escalated after Layla physically hurt Trout. Trout suddenly became even more serious, biting Layla’s back leg badly enough to badly injure her. This wound was deep and wide, as Trout grabbed onto Layla’s leg with all the force she had and then shook her head from side to side. Layla also had bruising and extensive swelling on the back side of this same leg, and I suspect that had we not intervened Trout would have continued to try to seriously injure or kill her housemate. Note that I don’t think that Trout initially meant for the fight to go so far. The earlier bites where she only bruised rather than puncturing tell a story of a dog who started something she wasn’t able to handle, then likely got scared and began to fight more intensely. Of course, guessing this is anthropomorphic and it’s entirely possible that there were other motivations driving Trout’s actions. However, since we can’t ask her and she can’t tell us, I can make a good guess about what happened based on the evidence at hand.

As you can see, knowing the level of commitment and seriousness that different bite locations and varying bite inhibition levels convey provides a great deal of information on the involved dogs’ intentions. They also tell us a lot about safety, providing insights into the future behavior and possible liability repercussions of working with any given animal. Any dog who has done damage to another in the past is likely to repeat that performance given the wrong set of circumstances, and it’s important to go into any behavior modification program with your eyes wide open to the future possibilities of working with your dog. As sad as it can be, I absolutely believe that euthanasia is an appropriate choice in certain dog-dog aggression cases if your dog’s past history indicates a serious danger to other dogs in the future. And of course, no dog who has injured another should ever be bred, as there’s often a strong genetic component to dog aggression.

However, that doesn’t mean that all dog aggression cases warrant euthanasia, and it’s also important to know that given sufficient management and training, dogs who have a history of causing harm can absolutely live out the remainder of their lives safely and happily. In fact, this is one of the most common behavioral cases I take on, as I love helping people have success with their dog aggressive or reactive dogs.

Next week, I’ll discuss what I did to keep Layla and Trout safe after their fight. In the future, I’ll also discuss what I did to help the two girls learn to live peacefully with one another again. I’m happy to report that, other than some lingering weakness in Layla’s hind leg, both girls’ injuries have completely healed, and they’re back to coexisting well. In the meantime, have you ever witnessed a dog fight? What did the injuries tell you about the dogs’ varying intents? Please share your experiences in the comments section below!