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Dog Suddenly Aggressive Towards Other Dog In the House

So what should you do if one dog is being aggressive towards the other dog in your own house?

Some dogs may even attack their fellow canines, leaving owners with lots of questions.

Whether it’s about reintroducing the dogs or the question of whether or not they should be separated after a dog fight and what line one should draw when it comes to the safety of other members in the house.

While it’s always saddening us to witness our beloved dogs fight each other, the problems are often pretty easy to solve if owners are ready for workarounds and training.

You’ll learn how to spot the signs of how serious a dog fight is (or was if you’re coming home too late), what to do with them and how to work on this issue.

My Dog Keeps Attacking My Other Dog For No Reason

Many owners report one of their dogs fighting with each other for no apparent reason.

While it may seem like our dogs just go on murderous frenzy out of nowhere, that’s actually almost never the case.

Dogs always communicate using their body language which includes facial and vocal gestures like growling, body postures, and tail positions.

We humans can sometimes have a hard time reading theses signs but even though threats can be pretty clear to dogs, they too can challenge their fellow canine. And sometimes both refuse to back down.

In other cases, it’s just known issues that one dog has and the other doesn’t, as is the case with food aggression.

While the aggressive dog may have initially triggered a dog fight, your other dog might as well be the first to attack. Every dog has a different threshold of what they take.

Keep in mind that it’s never your dog’s fault, some dogs just have a tendency to take less bullying than others and they might strike the provoking dog.

As a responsible dog owner, it’s your responsibility to take precautions if one of your dogs has known issues like resource guarding, food aggression, not wanting to be annoyed by your new puppy, and so on.

We’ll dive deeper into this in the bottom section where we discuss why dogs fight and how to solve it.

Dogs fighting with each other at home

Why Is My Dog Suddenly Aggressive Towards Our Other Dog

While your dog might not outright attack the second dog in your household, signs of aggression can be a tell that something might happen in the future.

How can your dog display aggression towards your other dog?

  • Growling or snarling upon approaching
  • Baring teeth when food or toys are around
  • Snapping your other dog when overexcited
  • Redirecting leash reactivity towards other dogs
  • Bullying the weaker (usually smaller or younger) dog

These signs can all be perceived as aggression and can be indicative of future problems that might arise.

A very tense relationship is never welcome and should be resolved immediately upon being spotted, but what can you do?

How To Stop Dogs From Fighting In the Same Household

When it comes to stopping your dogs from fighting at home (or outside), it’s important to note that I’m referring to constant nagging, snapping, growling, and so on – not any immediate threat or dog attack.

I have an article that covers the actual dog on dog attack if you’re interested.

To stop dogs from fighting, the most important question is why your dogs fight in the first place.

Once you know the root of the problem, you can take care of it.

So why do dogs fight?

  1. Resource guarding
  2. Food aggression
  3. Redirected overexcitement
  4. Lack of exercise
  5. Desire to be left alone
  6. Jealousy
  7. Pain
  8. Territorial issues / previous aggression

1. The basic explanations for fights with dogs are always resource guarding and food aggression.

If one dog is known to have either of these issues, please take care of it early on and read the linked articles.

2. If you walk your dogs outside or guests are over and one of your dogs redirects the negative energy to your other dog due to his level of excitement, training will be required.

If that is the case, it’s best to walk your dogs separately and work on the overexcitement with lots of new situations, dogs, humans, noises, etc.

The whole desensitization and socialization package.

My Rottweiler puppy was quite overexcited too (which presented as tension on the leash, nothing serious) and the causes and ways to solve this are almost always identical which is why I’ve written an article on this too.

3. If one of your dogs has a lack of exercise, this could be another reason why he is constantly nagging your other dog.

Besides extensive walks, there are several other things you can do to entertain your dog in your own backyard.

Make sure to adjust the amount and kind of exercise to your dog’s breed, age, and individual needs.

Sometimes this also means walking the dogs separately as they can have different exercise needs.

A tired dog is a good dog.

5. When people introduce a new puppy into the family, the adult dog might not be so happy.

Some adult dogs handle puppies very well and can be the best teachers, but other dogs just don’t have the temperament to deal with puppies in their face all day.

If one of your dogs constantly annoys the other dog, you have to keep this from happening again and teach them how to respectfully treat and measuredly correct each other in an appropriate way.

6. When you introduce a new rescue and he’s all the rave, neighbors come over and pet him, he gets all the attention, then that may be great for him but much to your other dog’s dislike.

Dogs can feel some form of jealousy and it’s important to teach your first dog to handle jealousy but also make sure that both get attention equally.

Pitbull jealous of other dog

Go on bonding trips together, make sure they connect each other with positive things and not with negative experiences.

Visit a vet to rule out any physical injuries.

You can check simple things like foreign objects stuck in the paw yourself.

7. Injuries are often not discovered right away and the resulting change in mood might be perceived as aggression if there’s another dog in the household.

8. I’ve decided not to include “dominance” since many people immediately connect that to the outdated dominance theory in dog training.

However, if you introduce a new dog, issues can happen if the introduction to each other was poor or even non-existent (see below).

Whether you believe in pack theory or not, it’s important that your dogs listen to you and recognise you as the leader and guide in which case training will be far easier.

Dog on dog aggression can not only happen between males, but also between females or even male and female dogs (although this is the best combination in many cases if both dogs have the appropriate temperament).

If your new rescue has come with baggage in form of dog aggression, you can resolve the issues with the steps and articles outlined above that include socializing and desensitizing your dog to others in order to create a positive connection.

The assistance of a behaviorist may be necessary.

How To Tell If a Dog Fight Is Serious

If real attacks are happening, it’s time to quickly intervene.

After this happened or even when you’re just suspecting it, you should never leave your dogs alone if they’re not separated (and if that’s not possible, they should wear muzzles).

Muzzles are also mandatory if your dog is known to redirect any perceived aggression towards you, or other dogs and people.

I’d never recommend to anyone that they should let any dog fight “play out by itself”. That’s almost never the case.

While there certainly is a threshold when a dog attack gets really serious, you don’t want to get to that point.

As discussed above, if you spot signs of aggression, intervene and separate the dogs until you have a clear plan of what to do now and how to resolve any issues that may have built up over a long time.

How To Discipline a Dog After Fighting

While dogs do learn with proper guidance, corrections, and counter-conditioning, there’s nothing that you can immediately do that will resolve the issue.

Check out my ways of how to discipline your dog but keep in mind that a correction should always be clear, but measured as to not achieve the reverse effect of your dog losing respect for you too.

Separating the dogs is not a long-term solution, although it will work in the short term until you’ve figured out what the problem exactly is and how you can resolve the issue.

On the contrary, constant separation will put much stress on both dogs as well as yourself and other family members in which case a harmonic life isn’t possible anymore.

If you go so far as to isolate one of the dogs, it might cause even more issues and resentment expressed as aggression than before.

White brown dog lying on the floor

Reintroducing Dogs After a Fight

Reintroducing both your dogs in the same household is an important way for rehabilitation.

In some cases, poor introductions to the new family addition are the cause of the other dog’s non-acceptance.

Some dog breeds defend their territory pretty harshly since that’s what they’re bred to do.

If you’ve just dropped a new dog into the other dog’s territory, problems are bound to happen.

Make sure that any and all introductions to each other happen on neutral ground. Introductions shouldn’t start with head-on meetings either since this can make one of your dogs uncomfortable.

Start by having somebody else lead the new dog towards you and then just start walking with you and your dog in the front.

Next, you can start with the meeting where they sniff each other more extensively.

Some dogs do not have any issues with dogs inside their territory (like my female Rottweiler), it’s still good to take precautions to avoid any confusions.

My Dog Killed My Other Dog What Should I Do?

This is a question you’ll find on Reddit more often than you’d probably like to.

It’s a sad story, no matter what the circumstances were but it’s important to not stick your head in the sand and start addressing this issue.

The advice that’s spread by people that presumably never really read up about dog training and behavior can be really dangerous.

Next is the popular “just surrender that dog to a shelter” or even better “euthanize the dog”.

Nearly no shelter will take a dog that killed another animal, much less another dog.

Even if they did, they probably couldn’t train it and the dog would end up in the hands of a layman, without the slightest mention or explanation of the incident.

Euthanizing a dog for a mistake the owner made is also completely unacceptable in my personal opinion.

No matter how you look at this, falsely assessing your dog(s) and/or not taking security precautions like isolating one potentially aggressive dog from the other are mistakes.

We can’t fix the past, but we can act differently in the future.

Start training with professional help.

And I don’t just mean a certified trainer, I mean a really qualified behaviorist that has a proven track record and that you trust.

Be ready to put in lots of time, effort, and money.

If this is no option for you, it’s completely understandable.

Sometimes, circumstances in life make it hard to deal with these kinds of situations but you should at the very least try to solve the issue yourself (with professional help if needed).

In case you want to surrender the dog to a shelter or another owner directly, do your research, explain everything in detail and do not downplay anything.

Try the hardest you can and don’t blame anything on the dog.

A dog that has killed before can definitely be very dangerous and should only go out muzzled and not interact with other dogs unsupervised (or not at all, depending on what exactly happened during the attack).

To summarise this, dog on dog aggression inside your own home can be really sad to watch and if you feel helpless, remember that their is a way out to teach your beloved canines to accept each other.

Lots of problems are easy fixes with the right training and patience and if you have any questions along the way, feel free to ask them in the comments!

About Danielle

I am the founder of PawLeaks where I share weekly tips on dog training and behavior. Sharing a passion for dogs and helping owners to solve problems through understanding canine behavior and modification is my number one goal.

L. Copechal

Saturday 7th of May 2022

Ok here's a good question. I have a rottie shepard mix. She was the first into our home at 9 weeks old, and then we rescued 2 chihuahuas within 6 months of the rottie. The rottie is now 6 years old, and the female chihuahua is around 11 years. The rottie has attacked her 3 times. Once over food which we handled, the second we have no idea as to why and the 3rd was over water. I am the pack leader and have been so since the beginning all 3 understand that. My rottie has become testy with the older female chihuahua. Its not often but it does happen. My wife and I do not want to put the rottie down, but we're also not sure of what we can do. We take all necessary steps. The first 2 attacks happened when we weren't home. This last time was in our kitchen near the water bowls. I know dominance is an issue with females, as the rottie was in the home first, but the older female chihuahua is dominant due to age. So what can we do to stop the aggression. The rottie is laid back 99% of the time, but then there is times where she gets this bug up her duppa and gets aggressive for about a day. Please advise. I don't want to put her down as she is a good dog, but I fear that she might get aggressive with my grandson. Again she has only done this 3 times in the past 6 years, but that's still 3 times to many. I have read books, and done the walks to drain her energy. Is there anything else I can do? The first attack our neighbor heard it and told us about it when we got home. The 2nd 1 we cam home and there was blood on our kitchen floor. I thought maybe 1 of the females had gone in heat, until I found the older chihuahua hiding under my dresser with a puncture wound near the back of her jaw. Took her to emergency veterinarian and was told she had 2 superficial puncture wounds and should be ok. All are kept up on vaccinations so no rabies issues. My wife and I are at a loss on what to do.


Tuesday 10th of May 2022

Hello, I'm sorry you're going through this situation. First of all, putting your dog down should not be on the table since it's our job as dog owners to be responsible and train them and there's no indication your Rottie can't be rehabilitated.

The fact that it's a super powerful breed against two tiny dogs is concerning though. You had a lot of luck with these incidents, as it could've gone in a whole other direction. A Rottweiler with the intention to end a life doesn't leave a small puncture wound so that's good. Doesn't mean it'll stay that way though.

Your only option right now is to consult a professional trainer and keep them separated when you can't supervise them. Crate one of them, close the door, whatever to keep them safe.

By the way, this may not be dominance (the term is outdated anyway). As you describe it, there seems to be a dispute over resources such as food, water. This can potentially extend to toys, resting spots, attention. Please keep in mind that your Rottie could suffer from a medical issue too or that the smaller dogs could be the instigators (a home camera would help with finding out but again, it's best not to leave them alone for now).

Your last option should be rehoming which might be hard at that age, but definitely don't consider euthanasia as a first option.

Gail Evans

Sunday 1st of May 2022

Hi Danielle, great article thank you. We have 2 rescue girls we adopted in Spain. Coco is an English Bull Terrier x with Spanish Podenco (a hunting dog) anout 23kg and Dusty is a 10kg Bodeguero (like a Jack Russell type) x with we think a Chihuahua as she has bug eyes and is quite small. We got Coco who is about 8 years old from a rescue organisation around 6 and a half years ago. She had been at the rescue a year after being picked up off the street at about 6 months old. Dusty is about 7 years old. We literally picked her up off the street about 5 years ago. Coco is a bit alpha female it seems. She wees standing up, can be a bit clumsy/bossy sometimes pushing Dusty out of the way if Dusty is sniffing something interesting, but we have on the whole had no problems with them for 5 years. We travel frequently and they spend hours in the back of the car together, in a dog kennel on the ferry between Spain and UK, in dog kennels if we have a break for a few nights. They have not been buddies cuddling in their basket but they have been great companions. We have moved house a few times, but as long as they are with us, they have always seemed great, adaptable dogs. About 6 months or so ago in the garden, Coco had been getting a bit wound up as there isva cat next door so she was pacibg the garden fence sniffing and then the dogs 2 doors down started barking. The girls are both tennis ball mad and we had been throwing balls in the garden. At one point Dusty had got both tennis balls and Coco 'out of the blue' (to me) attacked her. She had her on the floor, shaking her by the neck. I had to hit her to take away her attention (not my proudest moment) and eventually got her off by dragging her by the back legs. Dusty was shaken and bleeding but the wounds were skin deep and got cleaned up. It took some time on all our parts including digging deep to not punish Coco but we seemed to be back on track. Until yesterday. Coco had been out in the garden and the cat was next door so she was doing her manic sniffing. ( the weather has been nice and garden not muddy so she isn't always loose in the garden). She had been back inside and relaxed on the sofa for a little while. I was getting my coat to go out so my partner was waiting for me with a dog treat in each hand for the girls. Dusty got all excited jumping about and Coco dived off the sofa and attacked her. This time was worse. I heard Dave screaming at Coco, so ran in and managed to pull her back legs again. This time Dusty has had emergency vet treatment, including stapling up her wounds and antibiotics etc. She is a brave little cookie and will be fine. But how do I trust Coco again? Both my dogs are loved so much and my responsibility is to keep them both safe. How can I look Dusty in the eye and make that promise? Should we consider rehoming (if anyone would have her) or even euthanizing Coco? I am devastated but this cannot happen again to poor Dusty. They jave been separated, but we have just allowed Coco out of the kitchen where she has been whining so she doesn't feel punished and make matters worse. Sorry for long post. Wanted to give as much detail as possible. Also relevant, Coco is nervous of strangers to the house ( for first half hour ish but has never beem aggressive to a human. Apart from Dusty she has limited interaction with other dogs. Advice would be so very welcome. Thank you xx


Friday 13th of May 2022

Hi Gail,

it's surely a very difficult situation for everybody involved. Both incidents seem to be about resources (balls and treats) or perhaps your older dog just doesn't like the energy (i.e. getting excited about the balls and then again about the treats). At that age, it's essential to rule out a medical issue that's causing her pain and to act that way.

It's really difficult to say why this happened if it's gone well for years already. I'd really suggest you consult a trainer if both dogs are important to you. Rehoming, as you said, can be difficult at that age and with a history.

Euthanization should never be on the table if there's no indication that the dog absolutely 100% can not be rehabilitated which can only be said after lengthy sessions with multiple trainers specializing in aggression. It should never be the first or even second option.

Body language and the dynamic between these two is essential and you should really shell out the money and time by finding the right trainer. You've invested so much time into both these dogs and most of the time, there's something that can be done. It's good not to isolate one of them but still keep them separate when left alone and supervise their interactions. You can also read my article on how to break up a dog on dog attack, hope that helps if it's the case in the future but of course, the ideal way is to avoid them from happening altogether. That's why I'd recommend you act asap.

Best, Danielle

Stacey Tucker

Monday 24th of January 2022

We rescued a One year old chi and brought it home to our 2 year old chi. They got along very well for 2 weeks then all of a sudden our 2 year old started getting very aggressive with our rescue chi. He has been attacking him and snarling and growling at him, we have to keep them in separate rooms and I don't know what to do. Please help!


Tuesday 25th of January 2022

Hi Stacey, I'd suggest bringing in a behaviorist/trainer to check their behavior in person. It's hard to say why it's like this without knowing what may have caused this or how exactly they interact wth each other.

Angie Nicholls

Thursday 6th of January 2022

We´ve just adopted a 1 yr old Border collie female, Cali to join our family of a small 2 yrs old Spanish Podenco male, Harry and 5.5yr old cross collie/retriever male Mickey. We didn´t let her have free rein in the house at first, although she had lots of play time outside and played for long periods with Harry, and sometimes Mickey would also join in. Allan has been doing training with them and they were fine with this too. Cali would come into the lounge in the evenings on a lead and usually just went to sleep in a chair or on Allan's knee. Mickey and Cali went for walks together with my husband with no problems, Harry is very leash reactive, has been for the 11mths we´ve had him, so I take him separately and do training/counter conditioning on this with him. After 2.5 weeks everything seemed to be going fine so we allowed her into the lounge and kitchen with no restraint. This was fine for a couple of days, then on Saturday in the kitchen Mickey and Cali had a massive fight, and I tried to stop Cali from getting to Mickey by moving in front of her and moving my leg to try and stop her getting to him and I was bitten on the leg. We doused them with water and put them in separate rooms. The next day it seemed much calmer but on Monday morning when they were both in the lounge waiting outside the office door where my husband was (door was closed) another fight broke out. I used a water spray and they stopped but then Cali circled around and went for Mickey again, another jug of water had to be used. After that Mickey wouldn´t go into the conservatory where Cali is and for the last 2 nights has slept in the lounge as now whenever he's anywhere near, she barks at him constantly and Mickey is now barking back at her and we can´t risk another fight. He did try and get onto the settee where he normally sleeps in the conservatory (Cali & Harry sleep in crates) but he was too nervous when she wouldn´t stop barking at him, even though there was a cover on her crate. We have tried to analyze what might have happened to cause this problem but there was no food or other resource involved, unless it was jealousy as they are both very attached to Allan who does the walkis and training with them. We now don´t know what we should do, although Cali & Harry get on fine with no problems, we are seriously debating whether or not Cali should go, or whether de-sensitizing & counter conditioning techniques might work before the problem escalates even further. We don´t want to keep them apart forever, it´s unmanageable with 3 to have them in separate rooms, separate walks, separate playtime etc and obviously we just want them to all have access to the house with no problems so we are not babysitting them all the time. But, we can´t have WW3 breaking out every time they see each other, and we don´t want to stress out Mickey any more than he is, as he has Leish which can flare up with stress. Any advice would be much appreciated

Jennifer B Easterling

Friday 3rd of December 2021

All the sudden my German shepherd n my son dog which is part Australian shepherd has got into 2 fights n the last 1 almost ended badly my sons dog was lucky her neck was almost ripped thru .. n they have been around each other since we had them as puppies but they r both very protective over their owners I know my son dog is of me also and is very loveable to me at times I know my dog doesn't like the attention to be off her and on another animal but has never attacked 1 in this way.. it has really scared me and my nerves are shot still cause we been keeping them separated from 1 another but I can't keep doing this it is to much.. but I can see the aggression when they accidentally got in the same room with 1 another yesterday.. what do I do? How do I fix this?


Saturday 4th of December 2021

Hey Jennifer, separation definitely isn't a long-term solution and since aggression apparently surfaces even if they just catch a glimpse of each other, I'd definitely suggest you consult a behaviorist to help with this issue.

With overly protective/jealous dogs, it's important to know more about your daily routine, socialization of both dogs, etc. etc. and a professional should ask all the right questions and check the behavior in-person.