It's undeniable that when thinking of our canine friends, a mental image of a dog with its tongue hanging out is the first thing most people think of. Many may not be aware, however, of why this behaviour happens. In actuality, there are several different explanations for why dogs will stick their tongues out, depending on the circumstances. 

From panting in an effort to cool down to simply tasting the air around them, many factors contribute to this seemingly universal behaviour. It may seem like a small thing that goes unnoticed more often than not but understanding why this behaviour occurs can help us appreciate our beloved dog companions more than ever! Let’s look in more depth at some of the reasons why your dog may be sticking its tongue out.

One of the most obvious reasons most dogs may be sticking their tongue out, and one I’m sure jumped to the front of your mind, is that they are panting. Dogs pant for a variety of reasons, the most well known of which being that they pant in order to cool themselves down. 

Panting can also be a sign that a dog is stressed, excited, happy, or even in pain. It can also occur when a dog has been exercising hard and needs to catch their breath. Panting allows dogs to maintain body temperature regardless of the environmental conditions - it acts like an internal air conditioner! In fact, panting may be more efficient at cooling than a dog sticking its tongue out on its own because the act of using air currents to evaporate moisture in the dog’s lungs helps them cool very quickly. 

In any case, dog panting is a totally normal behaviour that can inform pet parents about what's going on with their pup's physical and emotional health. If they pair their panting with other physical actions such as shaking, then they may be trying to indicate that there is something wrong or that they are in pain. If this is the case, we recommend contacting your veterinarian immediately. 

Under certain unfortunate circumstances, dog owners may find their dog always has tongue out of their mouth, due to neurologic or anatomic defects, commonly referred to as “Hanging Tongue Syndrome”. This issue is most commonly seen in Cavalier King Charles spaniels, though other breeds can be affected as well. 

Typically, the dog's inability to retract its tongue properly causes difficulty when eating and drinking, leading to discomfort and malnutrition. If left untreated, this syndrome can cause chronic health issues for the dog. Fortunately, there are a number of surgical interventions that can address the condition and provide relief for the dog. With proper treatment, these dogs can live healthy and happy lives despite this issue. 

It is possible that your dog’s new medication is the reason why their dog keeps sticking tongue out. Certain prescription medications can cause a dog to become excessively panting or have their tongue out, especially if they have not been on a similar type of medication before. 

If your dog has an underlying illness, it may be necessary for them to take medication and this could explain the changes you are seeing in their behaviour. It is important to contact your veterinarian if you notice any concerning symptoms as soon as possible since some side effects of medications can be serious.

The flehmen response is a fascinating behaviour that is exhibited by many species, including horses and some dog breeds. It is characterised by curling the upper lip back, exposing the front teeth while inhaling with closed nostrils and often holding this position for several seconds. This response is believed to aid animals in collecting scents. For example, when dog's tongues hang out, they may be using the Flehmen Response to figure out an interesting scent or getting more information about a situation! It’s an incredibly useful tool for animals, which has been honed over millions of years of evolution.

Your dog’s teeth should line up in a “scissor bite,” with the upper teeth fitting neatly outside the lower. It is possible, however, for your dog to have an under bite or over bite which can lead to its tongue hanging out more than it should.

An underbite occurs when the lower jaw sticks out beyond the top. This affliction is also known as Canine Malocclusion and it's just as uncomfortable for your dog since their teeth are not properly aligned. As such, be aware of any changes in your dog's behaviour that could indicate discomfort and take them to your vet for regular check-ups.

An overbite in dogs is a serious condition that affects more than just the dog's appearance. This genetic condition can cause dental problems, speech impairment and even difficulty eating. Affected dog's may have an under-developed lower jaw, caused by a partial skeletal deformity making their lower jaw shorter than their upper jaw, resulting in faulty tooth alignment. You may recognise an afflicted dog by the characteristic protrusion of the upper canine teeth and the tongue often permanently hanging out of the dog's mouth. Thankfully advances in veterinary medicine makes it increasingly easy to identify and manage this abnormal jaw bone condition, with treatment options available to help alleviate some of these complications and improve the dog's quality of life.

If your dog's tongue is constantly hanging out, it may be an indication they are missing some of their teeth. Tooth loss in healthy dogs is usually a result of severe tooth decay or trauma to the mouth, both which can cause pain and distress. Without proper dental care and monitoring, serious dental problems can develop, leaving your dog with missing teeth. 

If left untreated, permanent dog tooth loss can occur, making it likely that you will see your dog's tongue hanging out frequently. It is important to take your dog to the veterinarian if you notice any abnormality in their teeth as soon as possible so they can get the treatment they need.