Why Does My Dog Open His Mouth When I Pet Him

Like it? Share it!

If you’ve noticed your dog opening its mouth when you pet him, you probably want to know why, if it should be a cause for alarm, and what you can do about it.

This post will inform you of the number of reasons why your dog might be acting this way,  if it is something you should be worried about and how to get him to stop, and if at all you should.

So, why does my dog open his mouth when I pet him? A common reason is that your dog enjoys it and loves it when you pet him. Dogs in fact open their mouth when they are engaged with an interesting activity. Other explanations could be that your dog feels nervous, stressed, thirsty, or in pain. It could also be that your dog wants to regulate him body temperature.

7 Reasons Why Your Dog May Open His Mouth When You Pet Him

There are so many factors to consider when attempting to figure out why your dog might be opening his mouth when you pet him. Once you’re aware of the reason, it becomes easier to figure out how and if you should get it to stop or just let your pup be.

Here are some of the reasons your dog might be opening his mouth anytime you pet him:

1. Your dog is happy:

dog opens mouth and happy when pet

Dogs open their mouths when they are playing and are getting excited. Your dog might simply be opening his mouth when you pet him because he enjoys being pet and lovingly stroked by you.

Many dog owners refer to this reaction as a “doggie smile” as it shows that your dog is feeling happy and content. If your dog is acting this way because he’s happy, you can tell from its body language. A relaxed and happy dog would also wag its tail and have a relaxed facial feature and bright eyes.

2. Your dog is thirsty:

Dogs lose water quickly in various ways, from their urine to their feces, from sweating and panting. When dogs are not getting enough water intake, they get thirsty, and if left for a long time, could result in dehydration. Your dog might be opening its mouth when you pet him because it is feeling thirsty. This is why it is essential to ensure your dog’s water bowl is filled with clean water all day long.

3. Your dog is suffering from respiratory issues:

Your dog opening its mouth when your pet might indicate that it is having difficulties breathing. It could be that your dog is suffering from pneumonia, which is caused by an infection and results in the inflammation of the lower respiratory tract or lungs. Again, observing your dog’s body responses should help you know if this is the case, as dogs suffering from pneumonia usually run a high fever, cough profusely, and show extreme signs of lethargy. If you suspect your dog has pneumonia, then you could contact your veterinarian for the appropriate professional care that your dog needs.

4. Your dog has an allergic reaction:

Just as humans have allergies, dogs have them too. Your dog might be opening its mouth when you pet it because it’s having an allergic response  [1]. This could either result from a new food you recently introduced to your dog’s diet or even a new medication. Suppose you notice that your dog is having difficulties breathing, is vomiting, or appearing lethargic just after introducing something new to its system. In that case, you should visit a veterinarian as this might be a case of an allergic reaction.

5. Your dog is just trying to cool off:

Dogs don’t sweat as much as we humans do, since they are covered with fur. However, dogs do sweat from their paw pads that are just about it. Sweating in humans helps to cool us off after a strenuous exercise or a tasking activity. So if dogs don’t sweat as much, how then do they let out excess body heat?

Simple, they do this panting. Panting is the way dogs release body heat into the atmosphere in exchange for cold, fresh air. Dogs do this when they get hot and even slightly warm. Hence, the hotter a dog gets, the more vigorous the panting gets.

Therefore, you might want to watch out for how long your dog opens its mouth when you pet it and how heavy breathing is, as heavy pants could indicate that your dog is overheating. Other signs to look out for includes redness of the gums and tongue, profuse drooling, extended tongue, wide eyes, and severe fatigue.

As a dog owner, you should take conscious steps to keep your dog safe and cool in scorching weather.

6. Your dog is feeling stressed and anxious:

Sometimes, your dog opening its mouth when you pet it might not be a sign of overheating. It might just be a sign that your dog feels anxious and burdened by some factors in its environment.

This sort of panting is known as behavioral panting. It is usually accompanied by signs like pacing, hiding away in secluded corners of the room, continuous yawning, licking lips, and shaking. Observe what might be causing your dog to feel stressed, was there loud noises at the time?

Did you take it for a visit to the veterinarian? Are there visitors around that your dog doesn’t recognize? Knowing the source of your dog’s anxiety would help you get your dog better.

7. Your dog is in pain:

Dogs open their mouths and give out intense breathe when they are in pain or suffering from an injury. So, your dog opening its mouth whenever your pet might indicate that your dog is in extreme discomfort.

Some other signs you could watch out to confirm if your dog is in pain include restlessness, growling, enlarged pupils, excessive grooming, difficulty moving, and reduced appetite.

You should remember that dogs love to mask their pain, as is their instinct; they do this because they do not like to show weakness or just from wanting to be alone. Hence, it is your duty as a pet parent to watch out for these signs and visit a veterinarian when you suspect your dog is in pain.


The truth is that to understand why your dog might be opening its mouth when you pet it, and you would need to analyze the overall situation and observe what your dog’s body language and response is. When dealing with pets, being observant is critical, as this would help you better understand how your dog is feeling and how to tackle any situation.


Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.