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.

IMG_1941After 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.

IMG_1943Layla’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.

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!

205 responses to “Dog-Dog Aggression Between Housemates Part Two: Bites

  1. I have a two year old male Pitt Bull mix and a four year old male GSD/Husky mix. Both are fixed and both have food aggression which was what initially started fights. We feed them separately which has helped. The Pitt is very protective of me and ever since I tried breaking up a fight and the GSD bit my hand the Pitt is even more protective. The last fight they had was over human food in our living room that I was trying to eat. They mostly bite around the ears and mouth, their claws get legs, and just generally it’s awful. We have an intact female that the Pitt is now acting aggressive towards if she cuddles me. We plan on fixing her but is there any other advice you could give? Would training be beneficial for both or just the Pitt?

  2. I have two pit mixes. One bites the other as if it’s trying to rip his ear off, and this incident has happened more than twice. Sometimes the other dog will just lunge and attack. The other dog is older and they both have been with us for a long time. Do you think euthanasia would be considerable for my dog that attacks my other old dog this way? They get along most of the time. The fights do get gruesome but I would hate to put him down. He’s only 7 years old and is not fixed. Do you think fixing him would be a better option or not as much?

    • I think you should get your dog fixed definitel, It will help. I have two dogs as well. An older pit and a Rottie/sheppard mix who is fixed but he does show some aggression over high priced treats…I cant imagine to put him down for this, but rather some serious training.

  3. I have two pitts male and female female was fighting with the male as I was petting both the male nudged the female away she started fighting with hi bite his ear at the end but she didn’t want to release I had a hard time getting her to let go yes bills every where

  4. I recently adopted a rescue, we have had her for 1 month. She is now 14 weeks old. Mom was a beagle/unknown mix and 50# and dad was a red bone hound and 70#, she will be getting spayed next Wednesday.

    She had become more agh with play, and biting my 7 year old golden to the point he has a puncture wound over his R hip. This is new. She bites everything and everyone…and has started lunging and snapping at my legs if I’m walking her on the leash. She is very stubborn and extremely hard to redirect.

    R/t covid I’ve been having problems finding in person classes, and finally have someone coming to the house tmr. I have been talking to my mom and sister but the day it’s just puppy behavior, but I’m worried that it’s aggression. She has bit me to the point I’ve bled, and my mother as well. She has been destroying the mat in the crate and anything she can get her mouth on. I do walk her, short training sessions and try to get her to play in the yard. What can I do to help her with the biting and behavior?

  5. I adopted a Plott Hound 1 year old.
    I have a mixed Pit roughly 10. The
    Hound is markedly pushy and aggressive. I watched and learned that my pit can take care of himself and generally stays apart yet they can share food, water and sleep on each other and play. But one time, I found canine puntures at the hounds lower throat above the breastbone. In my car they never disagree, but in the house and yard- the hound continues to bully. I found out since 9 weeks old- no socialization or correct training even allowed to kill and eat bunnies hares squirrels ducks . Both male. Any suggestions?

  6. My boy friend has a female pit and so do i they dont reside in the same house but we live next door anyways i say his dog attacked my dog (this is the 3rd time) he says she did not that it takes 2 ? but all his dog got was a gash on her ear all 3 times my dog though front paw practically ripped off the cavity of her chest and neck gashed open the tear tuck in one of her eyes torn really bad am i wrong for not wanting his dog around mine ?i am not saying his dog is a killer and its not that i dislike the dog i just dont trust her and he is not willing to admit it let alone work with her

  7. We were living with my cousin who has a 2 year old Pitt who has never been trained and we have a 4 year old small mix breed about 25lb. Hey Pitt was always following my dog around and playing too aggressively but one weekend (we were all out of town in house with 4 dogs) her Pitt went on a rampage. It took 2 small dogs (10lb) in her mouth on separate occasions like prey. My cousin thought maybe she was trying to play. Next morning she bit (attacked) my dog and 4 adults were around (I wasn’t) and she risky dismembered my dogs wrist needing a 10k surgery. She still maintains her dog was trying to play and said she was going to euthanize but her vet convinced her not to because the dog passed an aggression test. What do you think about this?

    • Good morning,
      First , a dog should NEVER be put down for attacking another animal . They are territorial. The pup is definitely trainable , no matter what hat the age .
      What should happen, is the pup should be placed in a home with NO OTHER ANIMALS OR CHILDREN!!!
      This happened to me recently. My dog Dakota killed my other dog Bailey. I was devastated. But I still loved Dakota even though she killed the other dog . So I placed he in a separate area till we found a prefect home for her . Now she is making a lady that just recently had brain surgery, better . She is loved and she is helping her new owner .
      Please never give up on the dog .

  8. A random miniature bull terrier went for my Westie’s throat. Her jaws completely covered Kirby’s (westie) neck on the underside, and she also had part of Kirby’s face and ear in her jaws. Abby’s (bull terrier) teeth were clamped down almost all the way in place around Kirby and Kirby screamed a nonstop heinous scream. I could not get her jaws off Kirby of course. Nor could the neighbors get Abby off. Finally the owner heard all the screaming and ran out of house and got her dog off. Was Abby trying to kill my Westie? We were in bottom 6 ft of Abby’s driveway and owner’s son left door open and Abby ran out straight for Kirby.

  9. I have two females who I have kept with a baby gate between them for a year due to fighting. The other day I got mixed up and let Kenzie, the younger dog almost two outside forgetting Sassy was outside. They were fine in the yard. But when they came in the house both with me hell broke loose. Suddenly there was a fight. What scares me is Kenzie will not let go even though Sassy is trying to get away. I tipped over a desk to separate them and it worked and Sassy ran off. But Kenzie chased herald attacked again. Kenzie bit Sassy on the leg. A deep and wide bite. I read your article and now I am afraid Kenzie was trying to kill Sassy. Kenzie has scratches on her nose but now bites. Kenzie would not stop until she was exhausted. I tried water, I threw stuff. I was alone so that is all I could do. Sassy in the past has always started the fight. When Kenzie was a pup and Sassy started something Kenzie would run off. But one day Kenzie had enough. Again, Kenzie has never started the fight. I know I have to keep them separated. To people Kenzie is the most loving dog. She is fine with my smaller dog. She is fine with the neighbors dog. I have learned if a dog starts a fight she will not back down. This may sound mean but I was thinking of getting mase or a low volt stun gun to have on hand Incase this happens again. I love them both. I would appreciate any advise.

  10. How did u stop the fight mine was bigger attack smaller and woujd not stop till I physically put my hand in his mouth lol he release his grip and I got bit

  11. Charlotte Powell

    My husband Jack Russell has attached each one of my chihuahuas has drawn blood on 2 of them it happened again last night and he refuses to do anything about it saying that she’s just misunderstood. I can’t have my babies living in fear of her we stay in my room now, I think the dog should be put down because she just won’t stop can you give me any type of advice

  12. My terrier mix keeps going at my tiny Maltese mix over treats. The last fight she bit her on the chest and drew blood just so she could get the treat! Now I don’t trust her with the smaller dog at all. My heart is broken. Now I may have to muzzle the terrier until I feel the small dog is safe. I will separate them when food is involved but it’s very scary. I will seek training for the terrier mix for this behaviour. The terrier is usually loving and playful otherwise, she is only 3 years old. They are both rescue dogs. Thanks for posting.

  13. I have a male 8 year old schnauzer mix and a female 6 month old Shepard mix . Both weigh around 35 to 40 pounds. Barney is very territorial and of course Sally is a big puppy and does what puppies do. They can get along 85% of the time only because I do not trust Barney and keep them separated as much as possible. To me, this is not the answer, I would love for them to get along or just be able to tolerate each other. It is mainly Barney., One minute he is fine, next minute he snaps bites her face and usually it is the eye area he hits. She has a scar on each eye now. I am getting them both fixed, but my question is what can I do in the meantime or do I just need to consider finding a home for Sally? Which I really don’t want to. She is a awesome pup. But I have had Barney since he was a pup and he is 8 years old, would getting them fixed help? I just don’t know what to do with them.

  14. I realized I’ve pulled up this page many times and never commented, and wanted to say how helpful this article had been in the past. I had two older neutered males, both around 15 lb, a Jack Russell and a terrier mix. They would scuffle unpredictably over “found goodies” like dropped treats about 3-4x a year the last couple years of the Jack’s life. Even though I’ve had dogs my whole adult life I’ve never had a pair of dogs that fight like these two did. It sounded absolutely terrifying. BUT, after the sound and fury they’d come away with at worst a nick on the nose or ear that never required stitches or any kind of medical attention.

    I considered going to crate and rotate but this article made me feel more confident that they were grumpy but ultimately harmless old men. It made me feel comfortable managing them by minimizing triggers, rewarding peaceful coexistence, and supervising all their interactions. I’m glad I didn’t decide to separate them because I think my mix was a great comfort to my Jack during the last months of his life as he declined. They spent his last few months cuddling in complete peace. It is touching still to think about and makes me misty.

    I wanted to share our bittersweet happy ending as a result of good, honest, thorough resources on housemate fighting as it is such a touchy topic and many stories in the comments of articles like this seem to end badly. Thank you again for giving me the confidence to let my little dudes be the best friends they ultimately were 99% of the time.

  15. I have 2 male pitbulls that are brothers. They have gotten in fights before but they weren’t as bad as today. Today me and my son had to break them up from fighting. I honestly don’t know why they started to fight either time, all I know is that it was going to turn out really bad if we hadn’t broke the fight up. One dog is mine and the other is my son’s and he just moved back home. What can I do to stop the fighting

  16. DANGEROUS dog ran across the street and went straight for Buddy’s throat while I was walking him on a leash. You are crazy for accepting this as territorial behavior.

  17. HELP! I have a 2 year old golden doodle who is a complete love bug! He’s been an only dog since I got him at 8 weeks old. My parents have a 10 year old Shih Tzu/chihuaha mix who was mine as a puppy as well, my parents have had him for the last 7 years.

    We recently had to move in with my parents and the dogs have had problems adjusting. They have both been the only dogs in each home. Neither dog has ever been aggressive. My dog has attended doggy daycare with no issues whatsoever. Last week the boys had a pretty significant and super quick fight that left the little guy injured. They scuffled over a treat that had fallen on the floor (both are food and toy territorial). We broke it up in seconds, it was so quick BUT the little one ended up needing surgery to have his eye removed. The vet did not find any other puncture wounds or anything else wrong with the little one, no bite marks whatsoever. We have of course kept them separated but it’s so heart breaking because they are both so sweet and loving. I have been told I need to rehome my doodle but he’s not in any way aggressive :-(

    How long should we keep them apart and is there any chance in them getting along?? I have enrolled my dog in training classes I am just super terrified that they will continue to fight.. :-(



  20. Susan J Hawkins

    I have a large mixed breed dog who is very territorial with me. She had severely bitten my other smaller dog a few times. I use a calming collar on her, give her calming supplements daily and it doesn’t seem to matter. She has had training but that was a while ago

  21. What about muzzle both while they are in the house?

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