Here at Zigzag HQ, we really love all puppies, but we also know how troublesome they can be and that things don’t always run smoothly. We know this isn’t an article you want to read, no one wants to learn about puppy aggression do they? It’s everyone’s worst nightmare to think their puppy might be aggressive. 

So… whether you think your puppy is displaying aggressive puppy signs, or you’ve been doing some reading up on puppy dominance aggression, we’re here to separate the fact from the fiction when it comes to puppy aggression, and also help puppy owners work out what to do.

In this article we’ll be going over

  • Signs: What aggressive puppy signs to look out for 
  • Is it play?: Figuring out if your puppy is really being aggressive or if they’re just playing
  • Why are they doing that? Reasons why your puppy might be displaying aggressive puppy signs
  • Nipping it in the bud: How to stop puppy aggression quickly
Photo by Justin Veenema on Unsplash

What aggressive puppy signs should you look out for?

So what should you look out for? Here’s a list of the most common signs of aggression in puppies. 

  • Freezing
  • Growling or snarling
  • Lip curling
  • Whale eye (where you can see the whites of their eyes more than when they are relaxed)
  • Hard stare  
  • Ears flat back
  • Body stance forward
  • Body hunched, tail tucked under
  • Snapping and biting (not to be confused with normal puppy biting though)

We have an article on how to quickly stop your puppy biting you that you might find useful to read through too.

Is your puppy aggressive or are they just playing?

So the reassuring news is that a lot of the time the untrained eye can interpret puppy play as aggressive behaviour. We know it looks rough, really rough but they are actually just practicing skills which lead to a greater chance of survival in the wild, or they are doing very normal puppy play behaviours. 

Puppies play rough – no really. Especially when they are playing with each other, it sounds like they are trying to kill each other in that wrestling match! All the snarls and growls! 

Sometimes they play like that with us too, and it can feel a bit scary, especially for children. 

We’ve put a little table together that gives you an idea if it’s play or aggressive puppy signs you’re seeing.

AggressionPlay
A low growl – accompanied with a freezeA high growl with lots of movement
Snapping and grabbingTugging
A forward body stance – often frozen A backward stance with bum in the air – often called a play bow
Stiff body posture – looks tightLoose body posture – looks wiggly
Tight furrowed brow – hard stare – closed mouthSoft face – open mouthed, lips covering teeth

By the way, is your puppy nipping you? Read our article on puppy nipping here.

Why is your puppy aggressive? Top reasons explained

Perhaps you’ve been told that your puppy displaying aggressive signs is them having dominance aggression. We want to reassure you that this label is old fashioned and really so called puppy dominance aggression and actually most forms of aggression are about your puppy being in conflict over something. 

There are other reasons you might feel that your puppy is being aggressive, and we’ve tried to give you some good explanations below to help you understand, and hopefully think about how you might tackle puppy aggression.  

  1. Overstimulation and not sleeping enough 

This is soooo common! Here at Zigzag we feel like we bang on about sleep all the time. Well you get fractious and irritable too when you don’t have enough sleep, don’t you? No surprise your puppy gets a bit snappy when they’re tired. This is often misinterpreted as aggression when really it isn’t, it’s quite normal. 

  1. Resource Guarding

They’ve learnt to be protective over resources – this often occurs when the over zealous puppy owner repeatedly takes ‘unsafe’ things off of the puppy without doing swaps. We want our puppy to think that swapping items is fun and taking things away from them should be no big deal, but we need to be careful we don’t end up with resource guarding related issues.

  1. We’ve told them off for growling 

When a puppy’s earlier signs of discomfort were ignored or even punished such as when they growl, they learn that that early warning sign didn’t work. Puppies and dogs generally give us lots of warning signs before they get to the biting stage. 

There is a saying ‘never punish a growl’ and it’s true because that growl was communicating something, and by punishing it we remove that early warning system and so they feel like they have to escalate to a snap, or a bite. 

  1. Dog-dog aggression – fear based

Maybe your puppy is scared of other dogs – dogs have a fight or flight system just like humans, If they can’t get away (flight) then they’ll typically have to use aggression to tell the other dog ‘I don’t like that’ this can then become learnt behaviour. It can be a result of inappropriate play at a puppy class or dog park, where you don’t get the switching of roles (i.e chaser becomes the chased, or puppy who was on top then becomes the one on the bottom when wrestling). 

Photo by hannah grace on Unsplash
  1. The frustrated greeter – dog/dog reactivity 

They’re overstimulated and frustrated about getting to other dogs – you know, that dog you see on their two back legs, snarling and lunging down the road. Well, some of those dogs started out as puppies who were allowed to go and say hello to whoever they pleased! Until they were told they couldn’t, making them hugely frustrated and turn into a snarling, hot mess.  

  1. Fear aggression

When puppies have missed out on early socialisation they can become fearful of many things, and react in an aggressive way towards them, sometimes for the rest of their lives. Puppies reared in poor conditions such as puppy farms with not enough stimulation or exposure to novelty, can become shut down or react aggressively when they experience something new.

  1. Territorial aggression 


Similar to resource guarding, though this time it’s not over a thing or object, it’s over a location or space. It might be a dog who guards their bed area from you or another dog, or it might be a dog who guards their house from that terrifying delivery man that’s come to murder everyone – just kidding, but that’s what puppies can sometimes think.

  1. Dominance aggression 

You may have heard of this label, that your puppy is being dominant or that they’re displaying puppy dominance aggression, but the honest truth is it’s not really a thing. It’s generally when there’s conflict between dogs, they’re not vying for any kind of hierarchical positioning or top dog; it actually tends to be more attached to resource guarding, and wanting the same thing. 


Dominance in the dog-human world isn’t really a thing either and has been disproved many many, times over. Dogs do what works for them that’s all, they’re not being dominant over you, we promise.

  1. Predatory aggression 

Another kind of aggression that gets talked about but is actually quite rare. All dogs have an Eye-Stalk-Chase motor sequence. This is how they learn to hunt and take down prey. For most breeds of dog, pieces of this sequence have been removed, it’s no good having a gundog who dissects the bird they are meant to bring back, but in a terrier it’s very useful to have that part of the sequence to ‘dispatch’ the rat! In some breeds of dog this sequence gets switched on to other animals at times, particularly larger dogs playing with small dogs. We call this predatory aggression or predatory drift. And yes thankfully it’s not too common, but just something to be mindful of if you have a little squeaky dog who plays with very big dogs.

How to stop puppy aggressiveness in its tracks

We’re here to help you overcome your puppy’s aggression, so have provided you with some info below as a starting point. Emotions have a huge effect on how a puppy behaves, so we will need to change how they feel in order to influence how they behave. 

We hope by reading this far down that you know it’s unlikely to be puppy dominance aggression, and that you’ve managed to spot the puppy aggression signs vs what puppies do when they’re playing. Here’s our top tips for stopping puppy aggression in its tracks. 

  1. Identify – is it actually aggression or is it just your puppy playing?

A lot of puppy play can look aggressive, but it often isn’t, so the first thing to do is find out if your puppy is actually being aggressive or are they just getting a little over enthusiastic during play?

Filming your puppy playing and when you think they’re being aggressive can be useful as you can watch it back later and see what was really happening. Turn the sound down and watch it in slo-mo – it’s fascinating!

  1. Find out what the triggers for your puppy’s aggressive behaviour are

Is your puppy guarding something they don’t want you to have or take away from them?

Have they learnt that biting/mouthing/growling stops you from ‘doing that thing’? Are they terrified of the courier, who knocks dramatically on the front door?

  1. Develop a structured plan to desensitize your puppy to the triggers, and work on changing their emotional response 

I know, it’s a lot of words, but it’s important if we want to change behaviour to get a plan together. 

For instance, if your puppy is guarding objects you’ll need to teach them that us coming towards them and taking things off them is a nice thing, and that they’ll get something better in return.

Similarly if your puppy is fearful of people and has learnt there are things they can do to make scary people move away (let’s be honest who wants a dog growling at them?) then you’ll need to teach them that nice things happen when strangers are around.

  1. Understand that your puppy isn’t GIVING you a hard time, they’re HAVING a hard time, help them learn to cope with things better and behave more appropriately.

Really get inside your puppy’s head and try to understand and have some empathy for the reasons why they behave in a certain way. Once you teach them there are other ways of behaving and those ways will be rewarding to them, they’ll start changing the way they think about things.

  1. Seek professional help

Particularly if there are biting incidents, you have children in the home, or there has been a sudden onset of puppy aggression, then seeking a professional dog behaviourist or dog trainer is something we strongly suggest you consider. They’ll be able to support you in training your puppy and give you advice on how to proceed.

With any behaviour problem it’s also an idea to get a vet check too, just to make sure your puppy is all ok health wise.

Photo by Jametlene Reskp on Unsplash

We hope you found this guide on puppy aggression useful, as always if you need help with your puppy, you can reach out to our Zigzag experts for help, via the Zigzag puppy training app. They’ll be able to give you strategies if it’s your puppy just playing a bit rough, or help you locate a professional trainer or behaviourist in your area if there might be more to it than just play. 

We also have articles on puppy growling if you want to learn more.