Brachycephaly means ‘short head’ ("brachis" = short and "cephalus" = head). Dogs with very short heads are called brachycephalic dogs.
Frequently Asked Questions about Brachycephaly:
In animals, brachycephaly is the result of selective breeding to produce offspring with very short skulls, especially the nose and lower jaw regions. This ensures that the snub-nosed appearance of the puppy is retained in the adult dog. With exaggerated selective breeding, an extreme type of brachycephaly occurs. Extreme brachycephaly is a man-made inherited disorder that results in severe life-long health problems for the dog.
Brachycephaly results, among other things, in deformation of all structures of the upper respiratory tract, dentition, middle ear, eyes and brain. Brachycephalic dogs are predisposed to upper respiratory tract problems, which are grouped under the term ’brachycephalic syndrome’ (BS). Characteristic problems include narrowing of the nostrils and nasal cavity, elongation and thickening of the soft palate as well as changes in the larynx and trachea. Extreme shortening of the nasal cavity leads to malformation of the nasal chonchae, which extend into and obstruct the normally empty respiratory passages (see Figure 5c).
The pug, French bulldog, English bulldog, Shih Tzu, Pekingese, Boston terrier and Boxer are the predominant brachycephalic breeds. There are of course brachycephalic dogs that have few or nearly no respiratory problems.
Yes, it is! Snoring in brachycephalic dogs cannot be compared to vocalization that expresses contentment or pleasure, such as purring in cats, or a form of communication, such as grunting in pigs.
Any narrowing of the upper respiratory tract that causes whistling or snoring noises is a sign of airway obstruction. Respiratory distress is always perceived as life-threatening.
When it is hot outside, we sweat, producing an evaporating film of water on a large area of our skin. The loss of the heat of evaporation that is removed from the body during the evaporation of sweat results in cooling of the skin and associated blood vessels.
Dogs are unable to sweat, but instead pant to cool down, which uses the same prin-ciple. Normal dogs have a large surface area within the nose, which contains an amazing array of delicate turbinates (Fig.1 No.3). Inhaled air travels over these structures, which are kept moist through glandular secretions, and cooling occurs via the same principle as sweating in people, namely by loss of heat of evaporation from the body. In brachycephalic dogs, however, the nasal conchae are too small and air can barely pass along them, which results in severely impaired thermoregulation. For this reason, brachycephalic dogs are particularly sensitive to warm temperatures and often require many hours to recover from exercise.
Brachycephaly also occurs in several cat breeds, including Persian and exotic short-hair cats, in which it may also cause severe respiratory distress.
Noisy breathing or snoring sounds, especially when the dog is awake, are signs of abnormal narrowing of the upper respiratory tract. A normal upper respiratory tract does not produce snoring sounds at rest or even during strenuous exercise. Brachy-cephalic dogs often pant, breathe poorly or not at all through their nose, have a low exercise tolerance and difficulty breathing when sleeping. Some brachycephalic dogs have difficulty eating because they cannot inhale sufficient air while consuming their meal. Some dogs regurgitate food several times per day. Unconsciousness and collapse are not uncommon in brachycephalic dogs that are exercised, stressed, subjected to warm temperatures or suffer from advanced airway disease.
Yes, they do. Unfortunately, this type of respiratory problem does not resolve on its own. During the dog’s life, narrowed nasal passages and subsequent increased res-piratory resistance lead to traumatisation of the tissue in the nasopharynx and larynx. Damaged tissue becomes thickened and causes further narrowing of the respiratory passages, thereby exacerbating the condition.
No, they have not. When one looks at pictures of pugs and bulldogs from 100 years ago, these dogs had distinct noses. In fact, back then the pug was considered an athletic dog capable of strenuous exercise; the German term ‘mopsfidel’ is still used and means ‘fit as a pug’. The breeding aberrations that led to the „noseless“ pug seem to have started 50 to 80 years ago and were the result of selective breeding for a baby-like facial appearance (’Kindchenschema’).
In principle, German animal welfare laws forbid this type of breeding: In paragraph §11b it states: "It is illegal, to breed vertebrate animals …when there is a high proba-bility that in the progeny, … certain body parts or organs that are required for normal species-specific function will be missing, unsuitable or deformed resulting in pain, suffering and damage." It is also illegal to show these animals (§12).
There are several surgical treatment options. Surgery is aimed at widening the nar-rowed parts at several levels of the upper respiratory tract: (1) The soft palate is shortened, (2) narrow nostrils are widened, and in some dogs (3) everted laryngeal saccules are removed. However, in extremely brachycephalic dogs, the results of these procedures are not always satisfactory and no appreciable improvement in breathing is achieved.
In recent years, we have discovered that obstructive tissue in the shortened nose may be another important factor contributing to breathing difficulties. Surgical reduc-tion of obstructing tissue using a laser provides an improved and open respiratory passage. This surgical procedure is called Laser-assisted turbinectomy (LATE). In the LATE technique, a flexible fibre (diameter = 0.4 mm) is advanced though an en-doscope and laser light (diode laser) is applied to vaporise obstructing conchal tissue very precisely. In addition, the soft palate is shortened and the nostrils widened using conventional surgical methods. In extremely brachycephalic dogs, conventional methods of widening the nostrils are often unsatisfactory. There is another new surgical method called vestibuloplasty, which also enlarges the nasal entrance and appears to yield even better results. Other new treatment methods alleviate the signs associated with laryngeal collapse.
Unfortunately, improper selective breeding has also led to other inherited abnormali-ties in brachycephalic dogs. In many dogs, the tongue is too big in relation to the size of the mouth (French bulldog) or the cartilage in the larynx and trachea is softer than normal, especially in pugs, and can result in collapse. Bulldogs often suffer from hypotrachea, in which the windpipe has a smaller than normal diameter. In many dogs the oesophagus is dilated near the heart, and the hip joints are often badly deformed. French bulldogs frequently have inherited vertebral abnormalities.
The teeth of brachycephalic dogs are too big in relation to the size of the jaws, which results in rotation of the teeth. This in turn leads to accumulation of food debris and bacteria on the teeth, which over time results in inflammation and loosening of the teeth. In growing dogs that lose their baby teeth, the adult teeth often remain within the jaw bone, which can result in bone cysts. In severe cases, these cysts may cause bone damage and fracture of the jaw.
Some of our recent studies also indicate that many pugs and bulldogs have severe abnormalities of the auditory canal and middle ear.
In contrast to humans, dogs must breathe through their nose; they are “obligate” nose breathers, so to speak. In fact, the canine nose is not only used to breathe and smell, but also to regulate internal body temperature.
Thus, every change made to a dog’s nose through selective breeding must be viewed with suspicion. A normal, natural healthy canine nose is a long nose. Each time it is shortened, there is a loss of essential function, leading to life-long health problems and impaired well-being.
For thousands of years, dogs have been bred primarily for a specific function, such as hunting, guarding or sledding. About 140 years ago, breed associations were es-tablished that not only bred working dogs, but also show dogs. At the very least, a working dog must be healthy and in sufficient physical condition to perform its duty, which constitutes a crucial selection criterion. When external characteristics become the main focus of breeding, without consideration of criteria that determine the use-fulness of a working dog, there is risk of compromising the health of the purebred animal. So-called ’stress tests’ that require the dog to walk for 10 minutes without difficulty, are definitely not suitable for determining whether an animal is fit for breed-ing, and even less so for correcting the mistakes made in past decades. The negative consequences of aberrant dog breeding programmes that affect the health of the animals were obviously recognized too late or not at all by lay people or, worse yet, they were simply ignored. The current state of health of many pure-bred dogs is alarming. It is obvious that the concept of dog breeding in the last 100 years has not worked and has opened the door to mistakes with serious conse-quences. Current veterinary medicine is complicit in the practice of maintaining dogs of breeds with inherited defects healthy and suitable for breeding. The demand for healthier purebred dogs is growing ever stronger and emanates from almost all continents. It is evident that a very important component of purebred dog breeding has been missing throughout its history: independent and professional quality control. The veterinary community must work harder in this area and law makers must realize that current laws are completely inadequate to halt the vanities involved in dog breeding. Considering all the mistakes that have been made in pure-bred dog breeding, it may be necessary to discuss whether breeding and selling of dogs should be licensed. The concept of dog shows must also be revised. Many judges and those involved in the selection of show judges have not served dog breeds well. Numerous judges still place an absurd emphasis on external characteristics, which in turn greatly influ-ences breeders to strive for the same. For example, even today a pug or bulldog with a “visible” nose has no chance of winning in the show ring. The production of unhealthy dogs will continue as long as international breed stand-ards (Fédération Cynologique Internationale, FCI) tolerate unhealthy breed charac-teristics. According to the FCI, a ’round head’ in the pug and a ’square head’ in the French bulldog are still a must. This excludes dogs with a “nose” from being bred and in effect, constitutes animal abuse.