I don’t suppose that it will surprise you to know that there are lots of potential reasons why your puppy becomes aggressive at night.
My list contains six possible reasons and six solutions.
And that some of these reasons, at first glance, might appear contradictory.
But, hopefully things will become a lot clearer as I explain a bit more.
But before I dive into explanations of my six reasons that puppies get aggressive at night, I quickly want to talk about bad behaviour.
How to stop your puppy behaving “badly”
Aggression is only one of many types of undesirable behaviours that we might want to stop.
And the best way of stopping any undesirable behaviour is to simply ignore it.
This is a skill that most of us find very hard because we like to use words to tell our puppies off.
And the trouble with using any words is that the puppy gets rewarded because by talking to them we have given them some attention- which is all they want!
As well as ignoring your puppy when they are showing aggression at night (or at any other time for that matter) you need to quickly praise them when they behave well.
And in the context of aggressive behaviour this means that as soon as your puppy stops being aggressive, you say “Good boy/girl” with lots of stroking as well if you like.
Have I made your head spin?
Let’s change the pace of things by looking at the first of my reasons why your puppy might be getting aggressive at night.
 Puppy is aggressive at night because they are too tired
Let’s start with one of the more obvious reasons for your puppy’s aggression.
And that is that they are aggressive because they are over tired.
Which is a perfectly natural state for them to be in.
After all it has been a really long day with lots of stimulation and activity but as evening comes round they really have had enough and are reaching breaking point.
They simply can’t take any more and they want to be left alone.
Or they are so tired that they don’t know what they want.
But they do know that they don’t want what you are asking of them now and their reaction is to be aggressive.
The solution to an overtired puppy who is acting aggressively is to calm them down and help them fall asleep.
And the best way of doing this is by making their surroundings as quiet and as calm as possible.
It could be that your over tired and boisterous puppy is displaying these behaviours because it is a routine to play an energetic or loud game with them.
This has to stop.
Instead of winding your puppy up with lots of noise and activity in the evening, try the opposite.
Use quiet voices and gentle activities such as whispering to them and stroking them gently as they are lying down.
And if your pup starts to get a bit lively, ignore them or soothe them and calm them down.
 Puppy is aggressive at night because they aren’t tired enough
I told you that there would be some contradictions, didn’t I?!
A few puppies might be acting aggressively at night because they are full of energy.
Having only just woken up from a really good sleep, they have bundles of energy.
So much so that they are coming across as aggressive, when in fact they just can’t contain their excitement!
The solution for this is that there needs to be a radical overhaul of the routine.
Your pup shouldn’t be full of energy late in the evening, as like people their bodies need to be relaxing and getting ready for sleep.
Of course, puppies are wonderfully random in how and where they choose to sleep but you don’t want your pup to have a long and deep sleep and then wake up just as you are off to bed.
Perhaps, instead of sleeping early in the evening, you can play a game of fetch with them for a short while or take them on a little walk?
 Puppy is aggressive at night because they have separation anxiety
For most of us, our dogs are like close family members.
And that means that they want to spend every waking (and sleeping) hour with us.
If you have developed a clear routine with your puppy, she might realise that it is night time and that the time when they are put to bed in another room, is approaching.
And her way of expressing her displeasure with you for even daring to leave is to be aggressive.
This is a tricky one because it really pulls at the heartstrings!
I think that the only way to fix this is to stick with your routine, however hard it may be to say “goodnight” to your little bundle.
And if your puppy cries once they are separated from you at night then the best thing to do is to ignore them.
The overwhelming majority of puppies with nighttime separation anxieties grow out of them once they understand that it is all part of a safe routine and that in the morning they get to spend more time with you.
 Puppy is aggressive at night because they have a phobia
In the same way that your puppy might act aggressively because they will be separated from you at night, it could also be that your puppy is acting aggressively because there is something else which scares them at night.
It could be that you have another dog which shares the same night time space as your puppy and this dog is behaving in a way which is scaring your puppy.
Or it could be that there is a particular noise that is scaring your puppy at night.
This noise might be a whole host of things- from a rogue smoke alarm, or a firework exploding to a nightly shouting match between an unhappy couple that your puppy might be forced to listen to.
Sometimes it can be hard to tell the difference between a touch of separation anxiety and a phobia.
As I have already said, most puppies will grow out of separation anxiety given a bit of time but phobias are not the sort of thing that they will grow out of.
Normally the cause or the trigger of the phobia needs to be erased as it is very hard to retrain your puppy to not see the phobia as a phobia.
So, for instance, if we take the example of a smoke alarm.
Smoke alarms are designed to make a terrifying noise that you can’t ignore because one day they might save your life.
And that ear splitting sound is terrifying to dogs as well.
Our smoke alarms went off by accident one day (by this I mean that there wasn’t any fire or smoke) whilst we weren’t at home.
And our dogs were so scared by the sound that they broke through one of our internal doors in order to get away from the sound.
I can’t train my dogs not to be scared of the sound because the sound is just so ear splittingly loud.
The only thing that I could do was to remove the smoke alarm from their room when we went out.
Sorry, I went off on a bit of a tangent there.
If your puppy is being aggressive and you know that it is because of a specific fear or phobia then the only solution is to get rid of the source of the fear.
 Puppy is aggressive at night because of “big changes”
Your puppy might be acting aggressively in the evening as a reaction to a change of their circumstances.
Dogs love routines and a puppy might get all grumpy when their routine changes.
Now the routine could be that you have moved house and so the puppy is having to get familiar with a new home.
Or perhaps you might have got another dog or cat and your puppy feels a bit threatened and shows that they have “sharing issues”.
Or it could be that there has been a change of personnel in the house. Has a new baby arrived?
Or perhaps someone special has left? Has a family member gone off to university or college?
Or has the family separated and a husband or wife have left? Or maybe a new partner has moved in.
Puppies are incredibly sensitive things and any of these changes can have a big effect on them.
And the most likely reason that your puppy is responding to these changes by acting aggressively at night is because they are already a little bit scared of the night and these changes are sending their stress levels even higher.
Because the causes of the changes can vary so widely, it is hard to write a specific one size fits all solution.
If the change involves getting another pet, you need to do everything in your power to make the other cat or dog be viewed as non threatening and friendly.
Also the addition of a new person into a family (whether it is a new baby or a new partner) needs to be a very positive experience for your puppy.
They need to be given time to adjust to the new circumstances and they need to spend lots of time with the new addition doing fun things.
 Puppy is aggressive at night because aggressive play is being encouraged
Nobody likes to admit that they might be in the wrong and I think that this particularly applies to parents.
Dog parents or human parents for that matter.
And it could be that your puppy is acting aggressively at night because you have taught him to be aggressive.
I don’t mean that you are training your dog to respond to the command “kill” but that you have started some sort of game with him and that he is getting over excited and a bit aggressive.
This is really simple to say and much harder to do.
If your puppy is acting aggressively at night because of an interaction between you then you need to stop it.
Puppies have very little self control and they don’t know the difference between play and aggression.
It is something that they will learn over time but you need to replace this type of play for something which is far more calming.
After all, the main aim of any time that you spend with your dog is to simply spend time with them!