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Why does my dog growl when tired?

It can be scary when your dog growls, particularly if they are growling at you. We often associate growling with aggression and biting, but it’s actually rare for growling to escalate to biting if the situation is handled properly. Growling does indicate a problem, but not quite in the way most people think. 

Why does my dog growl when tired?

Your normally friendly dog growls at you because they are tired, and leave you wondering what happened? Should you be worried? Are they about to bite? The good news is, it’s usually just the dog’s way of communicating.

Why Do Dogs Growl? 

Before we get into why your dog growls when tired, we need to look at why dogs growl in the first place. Humans have many ways to communicate that we want to be left alone. Dogs have their own cues, and growling is one of these. 

It’s essentially their way of saying, “I need space right now”, or “Hey, don’t do that”. If a dog is mentally and physically healthy and hasn’t suffered abuse, a bite is very rare. Their growl tells you, “Hey I don’t want to bite you, but you need to back off”. 

There are also different types of growls and associated body language. Dogs, particularly puppies, often growl when playing. It’s clear that it’s part of play by the tone of the growl and their body language. 

A warning growl is usually deeper than a play growl. A deep growl and snarling are often the last warning before a dog bites. 

You should always treat a growling dog cautiously. They are animals, and it’s possible for them to act out of character. However, it can be comforting to know that growling is usually a dog’s way of avoiding aggression. 

The Effects of Fatigue

Humans also get grumpy when they are tired, for similar reasons as dogs. Self-control and thinking take energy. When you (or your dog) get fatigued, there is less energy for these functions. Our brains route energy to what is most important for our survival first, and then to secondary functions like social etiquette and emotional control. 

Guarding Behavior

We often hear about guarding behavior being associated with treats, toys, and even owners. Dogs want to protect what’s theirs, and they can act aggressively to do so. An example of guarding behavior is your dog growling at you because you moved their food bowl or treat. 

Guarding is an instinctive behavior for feral dogs. Some domesticated dogs have no issues with guarding, while others will act aggressively if someone comes near their food or other resources.

It’s most common with food and toys, but dogs can also guard their sleeping area. Just like food, the dog believes that the area is his, and anyone who tries to usurp him is an intruder. If a dog is guarding his sleep area, he will growl if you get too close. 


Think about the moment you wake up from sleep. Are you thinking clearly? You are likely on autopilot in those first moments as your brain wakes up. Dogs are the same.

They have carefully honed instincts when sleeping. These instincts keep them safe when sleeping in the wild. If a predator finds a sleeping dog, the dog will have to react immediately. It won’t have time to think. The reaction has to be automatic. 

If a dog is asleep or dozing, they may growl if disturbed due to this instinct. 


Just like you, your dog dreams when sleeping. It occurs during deep REM sleep. The brain sends signals to the muscles to relax during sleep, which prevents your dog from jumping up and running around the house while dreaming. However, it doesn’t stop movement completely. 

If your dog is dreaming, you may see its legs twitch. Some dogs will move their eyes, even though they are closed, because they are looking around in the dream. Dogs can also make noises while dreaming. These include whining, barking, and growling. The noises your dog makes are a good indication of the type of dream they are having. 

If they are whining or growling, they are probably having a nightmare. Scientists believe dogs dream about the activities of the day, but no one knows for certain.

Experts say that you shouldn’t wake your dog from a nightmare. They may be disoriented when they wake, and this could cause them to act aggressively towards you. 

Why is my dog aggressive when tired?

It’s normal for a dog to be grumpy when they are too tired, but some dogs go beyond growling and get aggressive when tired. An aggressive dog is a scary prospect, but it’s important to understand what’s happening. 

Growling and Aggression 

You’ve probably been taught that growling means aggression. As we discussed earlier, this isn’t always the case. Sometimes it’s difficult to distinguish between growling and aggression. 

A growl on its own isn’t usually a sign of aggression. However, you should be concerned if your dog is snarling and growling, or simply snarling.

Freezing is another sign of aggression. The dog’s body will tense and they will appear to be frozen in place. This is a sign that they are extremely stressed. They may also make prolonged eye contact that appears to be a staring contest.

Lastly, they may snap at you. This is considered a form of aggression. However, it’s important to note that a snap is a warning and not a bite. If the dog wanted to bite you, they would. Instead, your dog is saying “Hey, stop or I’ll bite”. Never ignore a snap, because it’s likely the last warning you will receive. 

If your dog’s body is relaxed and they aren’t snarling, a growl is simply telling you they want to be left alone. If you notice signs of aggression in addition to growling, your dog is being aggressive.

Remember that aggression doesn’t mean your dog is bad. It doesn’t mean that the aggressive behavior will continue until you are injured or give up your pet. It simply means that there’s a problem that you and your dog need to deal with together.


If your dog is startled, they may react instinctively, just as they do when they are sleeping. If your dog is very tired, they will have less awareness of their surroundings. This makes it easy for you to unintentionally startle your dog. 

Discomfort or Pain

Discomfort or pain can make a normally friendly dog aggressive. Once again, there’s a strong human parallel. Have you ever snapped at someone because you weren’t feeling well? It’s a common thing to do. 

One reason for this is because our brain is occupied with the discomfort, so there’s less focus on thinking actions through. Feeling unwell usually results in an unhappy mood, which can quickly turn to aggression. 

Why does my dog growl at me at bedtime?

There are a few reasons your dog might growl at you when it’s bedtime. These include being overstimulated or too tired. 


Dogs need downtime just like people do. Every dog is unique. Some enjoy lots of stimulation, while others prefer a quieter environment. However, every dog can get overstimulated if there’s too much activity for too long. 

Overstimulation can look like being overly excited. They may get the zoomies. It can also look like attempting to withdraw from the situation. They may go to another room or a quiet corner. They may lick themselves in an effort to self-soothe. Some dogs become destructive when overstimulated. They may chew on things they shouldn’t. 

Since bedtime occurs at the end of the day, your dog may have had all the stimulation they can handle for the day. They may growl to let you know they need time to be alone to settle down after a long day. 

Awoken From Sleep

If you wake your dog up when they are sleeping, they will be understandably cranky. They may growl at you because they aren’t happy you woke them up. They need their rest just as people do. It’s also tied into their survival instincts. If a dog doesn’t get sleep, they can’t function well. In the wild, this could cost them their life. 

Over Tired

Of course, the most obvious answer is that your dog is overtired. As we discussed earlier, being overly tired can cause your dog to growl. If your dog seems exhausted at the end of the day, this is likely why they growl. 

What to do about my dog growling when tired?

Many owners panic when their dog growls, afraid that they will soon bite them. Others attempt to assert dominance over the dog through numerous methods, including staring them down or holding them so they can’t move. Neither of these reactions is the correct way to handle your dog growling. 

Prevent Them From Getting Too Tired

If your dog only growls when they are very tired, the simplest solution is to ensure they get enough rest. You may need to adjust their exercise routine, mealtime, or bedtime. They may need some time to rest during the day without being disturbed. 

Watch for signals your dog is getting tired. Signs include a lack of interest in activities or treats, yawning, hiding, and panting. Keep in mind that physical activity isn’t always necessary to tire a dog out. Dogs can get tired from physical and mental stimulation. 

Ideally, you observe your dog and note when they are overtired. You can then give them time to rest before they reach exhaustion. 

Keep age in mind as well. Young puppies sleep 18-20 hours a day. Adult dogs sleep between 12-14 hours. Senior dogs sleep between 16-18 hours each day. Puppies and senior dogs need naps in addition to a good night’s sleep to get enough rest. Most adult dogs nap as well. Be sure your dog has a place to nap as well as sleep at night. 

Stay Calm and Recognize Boundaries

When your dog growls, you’ll need to stay calm. Be gentle but firm. Give them some space, but don’t leave the area completely out of fear. Consider why your dog is growling. Are they resource guarding the bed? Are they overstimulated? Did you wake them from sleep? 

Resource Guarding

If your dog is resource guarding his bed (or yours), use positive reinforcement instead of punishment. In most instances, using punishment with a growling or aggressive dog only escalates the situation. 

It’s best to not allow them to stay on the bed if they are growling. However, the last thing you want to do is force your dog off the bed. Instead, use a treat to lure them off the bed. Perhaps let them sleep somewhere other than the bed for a night or two. 

Give them a treat when they share their area with you. If it’s your bed, make them wait until you invite them onto the bed. If they wait, then they get a treat. This lets the dog know it’s your bed, without escalating the situation. 


Overstimulation should be handled similarly to being overly tired. You may need to adjust their schedule and give them more downtime. Observe your dog and see when they are overstimulated, and what was occurring beforehand.