4 min read


Why Do Dogs Always Have Their Mouths Open



4 min read


Why Do Dogs Always Have Their Mouths Open




A dog’s mouth is an important part of its breathing, cooling and communicating system. Dogs regulate their body temperature through their mouths and after exertion or when the weather is hot your dog will pant to cool down his body temperature. Your dog also uses an open mouth expression to show he is relaxed and happy. An open mouth with a gentle panting sound and soft eyes all add up to a happy canine companion. However, not all the signs from an open mouth expression can be happy ones and so it is important to know what else an open mouth could mean. It’s another part of ‘dog-speak’ and can communicate different messages to you from your dog.

The Root of the Behavior

Mother Nature has provided dogs with a very special cooling system through their mouths. When a dog has been very active or is very hot, panting sets off the cooling process. Normally blood flows through arteries in the mouth and nose at a rate of 700ml per minute. When your dog’s temperature rises due to heat or physical exertion the blood flow increases to 1200ml per minute and helps to cool your dog down. A gland in your dog’s mouth is activated to increase saliva and also increase the cooling system. The panting will sound like rapid breathing and as dogs don’t sweat like humans do this is their way of perspiring on a hot day. A small amount of sweat can be expelled through a dog’s pads on its paws but will not cool your dog down sufficiently. What an absolutely amazing feat of nature! However, this is not the only reason why dogs may have their mouths open. Moderate to rapid breathing through an open mouth is normal behavior but labored breathing or strained respiration could mean something else. 

If your dog appears to be overly stressed and its breathing is accompanied by whining or a whistling sound there could be a more serious problem. Sometimes in extreme heat conditions, a dog can experience heat stroke. A red tongue, wide frightened eyes, and even an elongated tongue will warn you of heat stroke. Stress, anxiety, and fear will cause your dog to pant with an open mouth more than usual. Dogs show pain and fear through panting. Try to remove the dog from the stressful scenario. If you think the panting is the sign of a medical problem look for possible diarrhea or vomiting and take your dog to the vet for medical attention. Excessive panting could be the sign of discomfort from bloat or a physical injury. Your dog’s mouth is a source of information for you and is the best way to judge the happy contented dog that every dog owner wants to have around. In a dog’s language, a relaxed open mouth with a bit of tongue hanging out is a perfect way of saying "life is great today."

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Encouraging the Behavior

Everyone in the dog-loving world wants to have the ultimate happy dog beside them. Your dog can smile at you and say ‘I love you’ unconditionally through its relaxed open mouth expression. Some dogs really appear to be grinning as the sides of their mouths turn up and they look adoringly at their owners. Labradors, noted for their soft mouths and gentle temperament, are particularly good at showing how much they love the people they are with. Soft open mouths indicate a calm submissive dog who just adores being in your company. Your dog’s outward calm state will confirm his healthy happy inward state and reassure you that all is well with your dog. Getting close to a dog’s open mouth and smelling bad breath could be an indicator of some dental problems or gum disease so if you want to enjoy that doggie smile and the odd kiss or two a visit to the vet may be in order to put an end to the proverbial dog breath. 

An open mouth with teeth bared is not the happy relaxed expression you would like to see so before you pull in for a close nuzzle make sure you read the signs and look for the relaxed and happy open mouth with gently lolling tongue. These are the key indicators of a happy dog. Generally, we know what makes our dogs happy. The evening walk, a trip to the park or the beach, a game in the garden or some favorite treats these are your dog’s favorite things. They make your dog sit and drool with his mouth open. Even when you have been away all day your dog will greet you with his wide open mouth and happy grin.

Other Solutions and Considerations

When you see your dog sitting in front of you with an open mouth you can be pretty sure your dog is a happy dog. The words he is saying spell out how loved you are and how good a dog’s day can be when all his needs are met. The rest of his body language will add to the picture of a happy dog. The open mouth that is part of a stressed fearful dog will be accompanied by other signs of stress through fearful eyes, cowering behavior and a tail tucked between the dog.s legs. The open mouth becomes a different source of communication. This dog needs your help and calming to get him to relax. The dog's open mouth speaks volumes to those who can read the signs and understand how their dog is feeling in different situations.


Understanding some animal behaviors can take you to the next level of enjoying your life with your dog. The open mouth of your dog is not only a vital part of his anatomy but also a way you can understand each other. According to Orkan Pamuk, "Dogs do speak, but only to those who know how to listen." Understanding the reason why your dog has an open mouth is a great way to become a good dog listener.

By a Shiba Inu lover Patty Oelze

Published: 02/06/2018, edited: 01/30/2020

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