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

Why Does My Dog Open His Mouth When I Pet Him

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 a number of reasons why your dog might be acting this way,  if it is something you should be worried about 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 in 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 his body temperature.

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

Why Does My Dog Open His Mouth When I 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:

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 relaxed facial features and bright eyes.

2. Your dog is thirsty:

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.

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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:

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. 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, 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 include 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.

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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, Were 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 breaths 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.

8. signs your dog is stressed from moving:

Mouth opening and panting are stress reactions in dogs.

Dogs, like humans, are subject to stress and anxiety. They may feel uncomfortable with a new experience, environment, or exposure.

For example, if you bring a puppy into your home for the first time, he may be anxious about his new home and may need some time to settle in.

Additionally, if your dog meets new people or strangers that he doesn’t know, he may feel uncomfortable when he picks them up and carries them. Then they show their discomfort by opening their mouths.

If you recently became a dog parent and he opens his mouth every time you or other people try to carry him, there is no need to worry.

Your dog is experiencing some form of anxiety about you, his new owner, your family, and (or) your friends.

You could let him walk alone instead of carrying him and gradually introduce him to new people.

Let them do other things to it, like petting and touching it, but don’t carry it.

1- What to do if your dog opens his mouth each time you pick him up

2.1 Take your dog to the vet

If you notice that your dog is having trouble closing his mouth every time you pick him up, the best thing to do is take him to the vet.

If there are symptoms of an underlying condition such as tooth abscess, trigeminal neuritis, toothache, cold, or hyperthermia, appropriate medical treatment can be provided.


The truth is that to understand why your dog might be opening its mouth when you pet it, you would need to analyze the overall situation and observe your dog’s body language and response. 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.

FAQs: Why Does My Dog Open His Mouth When I Pet Him

Is it normal for my dog to open his mouth while being petted?

Yes, it’s a common and often positive behavior. Dogs may open their mouths to express pleasure, relaxation, or submission.

Should I be concerned if my dog doesn’t open his mouth during petting?

Not necessarily. Dogs have individual preferences for expressing comfort. Pay attention to other body language cues to gauge their response.

Are there specific breeds more prone to mouth opening during petting?

This behavior is not strictly tied to breeds; it varies among individual dogs. However, some breeds may be more expressive than others.

Can mouth opening during petting indicate pain or discomfort?

In some cases, yes. It’s crucial to be attentive to other signs of distress and consult with a veterinarian if you suspect any health issues.

How can I encourage positive mouth-opening behavior in my dog?

Positive reinforcement is key. Reward your dog with treats or affection when they exhibit relaxed mouth opening during petting, reinforcing the positive association.