Dog-Dog Aggression Between Housemates Part Four: Training

Last week I discussed the management techniques I used to keep Trout and Layla safe and separate after their recent fight and resulting injuries. I cannot emphasize how very important management was in our success – without it, I doubt we would have ever been able to get the two girls back together. That said, there was still some work to be done. Today, I’ll cover the training and behavior modification exercises that we employed to reintroduce the two dogs to one another.


Starting right away, we began to do short sessions with the dogs on opposite sides of their gates or ex-pens. We would take the blankets off the gates so that the dogs could see one another, walk them within sight of each other, then feed them lots of treats. After 10-20 seconds of treating, we would walk one of the dogs out of sight and immediately quit feeding both dogs. The premise was simple – good stuff only happened when the other dog was present.

When we first started these exercises, the dogs were noticeably worried. Trout frequently stared at Layla and sometimes growled, her posture stiff and upright. Layla avoided confrontations, looking away and licking her lips, clearly frightened. This behavior on Layla’s part was quite surprising to me. In the past, she’s always been eager to engage if another dog started something, but I suspect that with her increasing age (she’s nine years old) and injured leg she just wasn’t feeling up to another confrontation. When Trout growled or postured, her handler instantly stopped treating or paying attention to her and walked her away, while Layla’s handler praised and treated her for avoiding conflict while also moving her further away. We never allowed growling or posturing to continue for more than a second before intervening. Remember, practice makes perfect – and we certainly didn’t want Trout to get better at these behaviors!

Within a couple days, these positive conditioning sessions began to show real results. Trout’s posturing became less intense and Layla’s appeasement signals likewise lessened. Both dogs began to visibly brighten when they spied their housemate on the other side of the gate or ex-pen, looking for their treats. They also began to signal in friendly ways towards one another, sniffing from a distance and returning calming signals. We praised them enthusiastically for any pro-social behaviors, and Trout especially seemed to really need this extra reassurance that she was doing well.

As she became less insecure around Layla, Trout’s posturing and growling melted away. This is an important point. Frequently, owners think that their dogs are growling because they’re pushy, mean, or status-seeking. However, much like Trout, these behaviors are often an indicator of a problem with insecurity. Imagine, then, the damage that can be done by punishing a dog for growling or otherwise displaying their discomfort. Not only would punishment have potentially suppressed growling and other very useful indicators of Trout’s comfort level, but it also would have completely reinforced her belief that she was correct to worry when Layla was around. By pairing Layla’s presence with good things (treats! praise! neck rubs!) and viewing any growling as information that the dogs were too close, we were able to quickly change Trout’s reaction to Layla for the better.

Oops! Sometimes we made mistakes. Here, Trout got way too close to Layla, and began to display whale eye and other signs of tension. We immediately put more distance between the two dogs, and Trout once again relaxed.

Oops! Sometimes we made mistakes. Here, Trout got way too close to Layla, and began to display whale eye and close her mouth – both major warning signs. We immediately put more distance between the two dogs, and Trout once again relaxed.

At this point, we began taking short walks multiple times a day – just halfway to the corner at first, then all the way to the corner. We started by walking the dogs across the street from one another, moving them in the same direction but allowing for plenty of parallel distance between them. Both dogs were given treats for looking at the other dog in a soft manner, as well as receiving frequent rewards for walking nicely. If either dog began to look tense or nervous, we immediately veered further away from one another, giving them even greater distance. When they were both soft and relaxed, we moved slightly closer, lessening the distance between the two.

Within a week, the two dogs were able to walk side-by-side in a relaxed manner. They began sniffing each other as they walked, and following one another to especially enticing smells. They started to urine mark over special smells together. While they were still kept completely separate inside, their outdoor walks allowed them to start interacting as a team once again.

Inside, we continued to experience problems with guarding. Both dogs guard resources (food, toys, special resting places), so we had to be very aware of potential triggers. If either dog growled or stared at the other, the offender was immediately but calmly escorted to a crate or room for some alone time, while the dog who had been growled at was rewarded liberally with treats and praise for not responding. In just a few days, Layla began to run to the treat cupboard and wait for a reward during the rare moments when Trout happened to growl, and both dogs began to posture and threaten the other less frequently.

To begin working on reintegrating the dogs indoors, I returned to one of my favorite tools for behavior modification – the Protocol for Relaxation. This step-by-step protocol teaches dogs to relax while stuff happens around them, and both Layla and Trout were already quite familiar with it. I started running through the protocol once or twice a day, at first with the dogs lying on mats on opposite sides of a baby gate, and later with them side-by-side but with Trout tethered. After a week of successful protocol repetitions, when both dogs were looking soft and relaxed on their mats, I untethered Trout. Outside of training sessions the dogs continued to be kept separate, but while we were actively working on the protocol they were able to be loose together, relaxed on their individual mats.

These three main exercises – positive associations on opposite sides of the gate, parallel walks, and the Protocol for Relaxation – set the stage for a successful reintroduction. Within a week, we began allowing the dogs to pass by one another off-leash without interacting when switching them into different areas of the house, and later began to allow short (2-5 minute) periods of time when they were loose together but heavily supervised. We continued to keep them apart for the majority of the time, but built up the amount of time they could be around one another gradually.

Relaxing during the Protocol for Relaxation, off-leash together!

Relaxing during the Protocol for Relaxation, off-leash together and all healed up!

Reintroduction after a serious fight is a slow process, but it was worthwhile in the end. After a month of gradual reintroductions, we were able to take the ex-pens and baby gates down completely. The dogs continue to be separated if left unsupervised (something we’d done prior to this incident as a matter of course), but are otherwise peacefully coexisting once again. Three weeks into this process, the two began playing together once again, at first with frequent breaks and exaggerated body language, and then with more relaxed signals as they once again became comfortable with one another. Today their interactions have returned to the pre-fight levels of peace and playfulness.

While I’ve coached many, many clients on reintroductions such as this, I’ve never before experienced inter-dog issues with my own pets at such a serious level. I can empathize with the stress and anxiety of dealing with dogs who don’t get along. My mantra for clients in similar situations has always been that “slow is fast,” and Layla and Trout were proof that this is indeed the case. Anytime we tried to rush through exercises or pushed the dogs, things fell apart. Allowing both girls time to heal, physically and emotionally, and setting them up for success with one another, gave them the tools to progress at their own paces and eventually to rebuild their relationship. We’ll continue to be vigilant in avoiding situations that could trigger a repeat of their fight, however I feel confident in saying that the dogs are better equipped to avoid conflict in the future due to the hard work we put into helping them succeed during this time.

If you’ve ever experienced inter-dog aggression in your own household, I hope your experiences at reintroduction were every bit as successful as ours. Remember, slow is fast, and it’s important to work at your dogs’ own paces. Feel free to share your tips, tricks, and stories in the comments section below.


12 responses to “Dog-Dog Aggression Between Housemates Part Four: Training

  1. Wow – great work, lovely post and well explained! Ruth Date: Tue, 9 Jun 2015 11:03:20 +0000 To:

  2. Have enjoyed reading your series on dog fights and bites. I have lived with multiple terriers since 2000 ; I fostered and failed several times. Now those elder male terriers who were so well behaved have died. The younger females can be quite ugly to the senior female. Something to consider is the age differences of the dogs and how fluid hierarchy is with multiple dogs. I had no difficulty returning a Jack Russell to the rescue I fostered and then adopted her from because she tried to take out the female dachshund who was a maternal, kind dog. The Jack simply was maturing and status seeking. I did not need that. The Jack was successfully placed in a home with a larger male. No regrets. Sometimes, we humans need to consider the stress we put on our dogs if they continue to rehearse the fighting. Nobody should ever feel like a bad owner for rehoming one of the dogs. Generally, my terriers might have a skirmish or issue a correction to another dog simply in teaching manners. Nothing like the fight you describe between Trout and Layla. It does sounds like Trout got frightened at Layla’s lack of bite inhibition and figured she better get serious and thus the fight escalated. Good luck in your management. It sounds like you are on the right road, taking incremental steps. Look forward to reading more.

  3. Anne Manninen

    Thank you so much for this series. My boys have fought repeatedly over the past year and a half or so and it’s such a lot of work to try to fix things. Most fights after the first one have been triggered by factors mostly outside of my control (e.g. while I was at work, someone left a baby gate open, then stepped on a dog’s foot while everyone was crowded at the door), but I’m left to pick up the pieces.

    Reading this made me feel better about the work I’m doing among all the “just give one up, it’s just a dog” type of so-called advice. It also helps to hear I’m not alone and that maybe all this isn’t just my fault. Thank you.

  4. I stumbled upon these articles on FB. I am thrilled to have found them. Knowing that this happens with other dogs, makes me feel a little bit better about how I have trained my dogs. Reading the extensive injuries your dogs both sustained from their behavior, makes me feel a bit relieved about the outcome of some of the fights at my home between my dogs. I have 3 Chi’s & a Puggle, The Chi’s have all been raised together their whole lives, the puggle is a foster failure (lol). The 2 male chi’s Sid & Bear are the issues. Well it’s Sid that has the issues. Things have calmed down drastically over the years, but Sid just attacked bear yesterday for the first time in 8 months, and he had every intention of hurting this dog badly, had I not intervened, so I am not sure why he did it. Sid is very jealous of Bear, I blame myself for this because I pamper that little dog. Bear only weighs 5 lbs. He can’t even defend himself. Once Sid gets him in his grip, the other dogs all chime in and this little dog gets it from everyone. I found the interesting part of your article about where the dog actually sustains the wounds on the other dog. So, after reading that and knowing how Sid attacks Bear when he can get at him, it’s never on the neck or chest, always grabs a back leg to hurt him , but not kill him. The strange thing about this whole issue with Sid is I can walk them together, go for car rides with them both, have them in the livingroom together with no issues. It’s when I let Bear into the kitchen to let him outside that Sid goes on the attack. He acts so vicious, that I have to kennel Sid, so he can’t get at Bear. Sid is in the kitchen with the puggle, so I am thinking that is his territory. Sid doesnot do this with any other dogs, just bear. Sid did bite a small boy 2 weekends ago when we were camping, but I Know exactly what he was thinking when he bit that boy, Sid was teased and harassed by some boys next door, sticks poked at him and taunting him, he hates kids now. When I saw this happening I intervened, but it was too late. That day he bit that little boy, I had sid on a leash tied to my chair while I was fishing, I am sure he had been eyeing that boy for sometime, but the boy got closer to us, sid got loose and ran right after him and bit his leg. Didn’t break the skin, but did bruise him. I felt so bad for that little kid. I explained to the parents why he did it. Sid has never bit anyone before, but he has his moments where I don’t trust him. So, I don’t put him in the predicament where he can do harm to anyone. I do use a muzzle when I have to. He gets really depressed when I put that on. I think part of his issues stem from genetics. I have a Pet Sitting Business in my own home & I foster dogs for an animal rescue. Sid doesn’t have any issues with any dogs that come here. So, again I blame myself for pampering my little bear bear and Sid is resentful for sure. I try to give them all equal attention. What I notice through all my dog interactions is the smaller the dog, the more the “Napoleon” Syndrome sets in. My female Chi will take on any size dog at any time if she feels threatened. What I have learned is any dog can bite at any given time and it’s mostly out of “fear”. The bigger the dog , the gentler they are. I have learned a lot of your article. Thank You!

  5. Sara –Thank you for sharing your experience and writing the insightful articles. Our agility instructor shared them with us after our two Springer Spaniels had a series of fights, the most recent two resulting in injuries requiring medical attention. It has been 3 weeks since the last fight and we have been following your guidelines, including separation, the relaxation protocols (they are now tethered next to each other), parallel walks moving closer together (they walked next to each other over the weekend) and counter-conditioning when they are on opposite sides of the gates (we now see more relaxed, happy looks). We have been embracing the “slow is fast” mantra and are ready to let them interact a little more. We had a couple of questions for you. First, do you think it is detrimental to wait too long to reintroduce them? I know you did it with a month…we are at 3 weeks and are seeing much calmer behavior but haven’t let them together except through the gate and on the parallel walks. We just started changing zones unleashed with strict supervision over the weekend. The relaxation protocols are really having a profound impact but we haven’t yet let them interact without leashes or gates at this point. Our second question is…one of the dogs is our 6 year old female (Riley) that we have had since she was a puppy. The other is our newly adopted Springer (Libby, 2 yo female). Would you change any of the recommendations when they don’t have a long history of co-existing peacefully? We adopted/rescued Libby in May, so have had her for 4.5 months. Just wondering if you would change anything, given the new dog/old dog scenario. Thanks for any feedback you might have!

  6. My dogs just fought right now 12:52am we usually bring them inside at night because it gets very cold leave them in the garage. I have Two pit terriers. Both males. They are about 7months right now. I just divided the garage in half Shadow but Casper in the nose witch left blood and on his side upper shoulder. Shadow looks to be unharmed but looks very sad and upset in the corner. What should I do next?

  7. Ive been training my dog too i know the knowledge ive got from this will really add up to what ive been reading lately in this new dog training ebook.. really makes things much easier

  8. Question! So what if it’s not a resident dog but a dog who visits very frequently! I have a foster (soon to be foster fail) and a previous foster (my friend’s dog) that I dogsit often. They have been in two fights. Both young adult males (1.5 ish). Both have had issues with food aggression, but both have worked on that and haven’t shown any signs towards another dog besides each other. One fight was over food… my friends dog initiated, though ours did tear his ear a bit. It was the other dog who initiated last time as well over a toy

  9. Pingback: Top 13 How To Reintroduce Dogs After A Fight Lastest Updates 08/2022

  10. Would you consider this same approach if the dogs fought in July 2022 and can’t hear each other let alone see each other without trying to fight since? And it’s full on barking, growling, jumping on the door. I’ve tried reintroducing while the youngest is in the cage and she tries to bust out. The youngest (2) is the aggressor, and there have been about 5 fights (three have resulted in vet visits and I’ve gotten bit once) since July and constant tension. on 10/31/22, my middle (3, the biggest dog and who the little wants to attack) got out of the backyard and came to the front yard. The youngest (aggressor) saw her, busted and jumped through the screen on my screen door to attack her and succeeded. I have my oldest dog (6) who is the smallest and her and the youngest get along for the most part, but I’m seeing the same signs happen. I know it’s a matter of time before she’s attacked, too. She doesn’t react like my middle but I know the minute she does it’ll be over and i don’t know what to do. I’ve tried to find a home for my youngest where she can thrive, worked with the shelter, contacted a couple of trainers and it has gone nowhere. The major fight in July happened after I got back from a weekend away. My sister was here with her male dog and there were no fights but I got back and there were 3 in three hours. I wasn’t sure if I was actually her trigger until the signs started happening with my oldest recently. If you read this, thank you.

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