© Therese Rodin
Background: I have not found any articles published in scientific journals on this topic but I have found some articles written by Fraser Hale who is a board-certified veterinary dental specialist engaged in the dental health of brachycephalic dogs (and cats). Hale’s articles are very informative even though it is clear that he is against the breeding of brachycephalic animals (which can be seen in their titles below). In fact, as has already been visible in the section about BOAS, we have to move away from extreme brachycephaly if we want to save the Pug breed and have healthy Pugs.
Hale lists several issues that he encounters in the mouth of brachycephalic dogs:
- Teeth get in abnormal contact with other teeth and/or soft tissue and cause trauma
- Traumatic swelling of the inside of the cheek because of abnormal contact of teeth
- Teeth are crowded and/or rotated which increases the risk of periodontal disease (diseases related to the teeth and their surrounding tissues)
- Not fully erupted teeth that lead to inflammations in the tissues around/above them
- Un-erupted teeth that lead to the formation of cysts
- Accumulation of fur in deep folds in the palate
- A too wide and loose joining of the left and the right side of the lower jaw
Hale writes that “Not every brachycephalic dog has all of these problems, but virtually all have some of them.” He also points out that these oral health issues are not only found in brachycephalic dogs but they are much more frequent among them.
Already the underbite of the brachycephalic dogs can cause abnormal contacts of teeth to other teeth and/or to tissue in the mouth. In a dog’s mouth on each side, only the two upper molars (the large teeth furthest in the back of the mouth) shall be in contact with the three molars in the lower jaw. The other teeth shall not be in contact with each other. However, almost all dogs that have an underbite have abnormal contacts with teeth and/or tissue, which causes pain and can cause trauma to the exposed teeth. Furthermore, a tooth that has contact with the gum where another tooth shall erupt can prevent the eruption of the latter. When there are painful contacts between teeth and/or tissue, Hale recommends that the teeth that cause the pain are removed.
The reason why teeth are crowded or rotated in brachycephalic dogs is that there is not enough room in the mouth for all the 42 teeth that a dog shall have. (As a matter of fact, small dogs often miss some teeth, and it can be seen as an advantage since then there is more space for the existing teeth.) When the teeth are crowded there is no space for gum between the teeth and each root has less support from the bone in the jaw. The lack of space between the teeth makes it easier for plaque and bacteria to accumulate and it is more difficult to keep the teeth clean. That as well as the little bone support almost inevitably lead to inflammation and loss of teeth. A rotated tooth also has less bone support than one that sits properly.
The crowding of teeth can also result in the un-eruption of some teeth. A tooth that is un-erupted can be the cause of the development of a cyst in the dog’s mouth. Before a tooth has erupted it is surrounded by a sac of tissue, which bursts where the tooth erupts. If the tooth does not erupt this sac remains intact and inside it a cyst can develop. If a cyst develops, it presses unto the bone that atrophies. It can press unto the bone and roots of adjacent teeth and destroy them.
At the age of six – seven months the dog has got all its permanent teeth. At that time the teeth should be counted and if there are teeth that are not visible the dog should be X-rayed. If there is an un-erupted tooth it should be removed in order to prevent a cyst to develop. In some cases the dog just lacks that tooth and then everything is fine.
Some teeth under-erupt because of lack of space in the mouth. In that case part of the enamel that should be above the gum line is instead below it. The gum does not attach to the enamel and therefore this causes large pockets around the teeth where bacteria can go down and destroy the root of the tooth. Surgery can be done to uncover the enamel and sometimes teeth have to be removed.
In the palate of a dog, there are stripes that protrude and in between them are “valleys”. In brachycephalic dogs, the stripes are often pressed together and this can lead to the accumulation of fur, food and bacteria between them. If this is not noticed and removed, an inflammation of the palate can develop and the dog will need veterinary treatment. Hale suggests that if you own a brachycephalic dog that has such crammed stripes in its mouth, you should brush also the palate when you brush your dog’s teeth.
Goal: The dentition of Pugs shall be normal and healthy.
Strategy: It is essential for the dental health of the Pug to get a longer muzzle. On the way to a normal dentition in the Pug, all Pugs should have a thorough dental check at the age of six – seven months. Pugs with severe mouth and dental issues should not be used in breeding. Through an elongation of the muzzle, which is also part of the strategy to come to terms with BOAS, the palate of the Pug will normalize and the teeth will have enough space in the mouth. This will be done on the one hand through selection of Pugs with longer muzzles for breeding, and on the other through crossbreeding.
Sources and further reading:
All these articles can be found on Fraser Hale’s web page:
“Dentigerous Cysts: An Avoidable Catastrophe”
“Periodontal Disease – Again”
“Stop Brachycephalism, Now!”
“The Anatomy and Physiology of the Periodontium”
“Why do I say ‘Stop Brachycephalism Now!’?”
Chapters in Strategies for the breeding of Healthy Pugs
- Hips, Elbows and Patella
- Hemivertebrae and other vertebral anomalies
- Spinal Arachnoid Diverticulum (SAD)
- Pug Myelopathy (PM)
- Degenerative Myelopathy (DM)
- PDE/NME and other non-viral induced encephalitides
- Brachycephalic Obstructive Airway Syndrom (BOAS)
- Dentition and mouth health in the Pug
- Eyes (Brachycephalic Ocular Syndrome)
- Mating and Fertility
- Genetic diversity