Brachycephalic dog awarenessDiscussing health issues more commonly seen in brachycephalic dogs
Dogs with a flat, wide shaped head, are said to be brachycephalic (brachy, meaning short and cephalic, meaning head). This particular skull shape will often give these dogs a characteristically flattened face and a short muzzle.
Brachycephaly occurs across a spectrum, from breeds with almost entirely flat faces (sometimes termed ‘extreme brachycephaly’), such as the Pug and English Bulldog, through to less exaggerated brachycephalic dog breeds, such as the Boxer and Staffordshire Bull Terrier. Brachycephaly is not restricted to purebred dogs – crosses that include these breeds can also exhibit this face shape. It is also a condition seen in certain breeds of cat and rabbit.
In the ten years to 2017, there has been a rapid rise in ownership and number of brachycephalic dogs in the UK (both those that are Kennel Club-registered and in the wider dog population1). According to Kennel Club figures, registration of these breed types has risen dramatically over the past ten years, with a 3104% increase in French Bulldog registrations, a 193% increase in Pug registrations and a 96% increase in Bulldog registrations.2
Dogs come in many different shapes and sizes. Having such a varied appearance is one of the many fascinating things about dogs. Regardless of what each dog looks like, it should be able to lead a happy and healthy life. Some brachycephalic dogs, often referred to as ‘flat faced’ dogs, may be at higher risk of certain health conditions – the most widely recognised of which is difficulty breathing.
Brachycephalic Obstructive Airway Syndrome, or “BOAS” is a collection of issues commonly seen in brachycephalic animals including narrowed nostrils and elongation of the soft palate, which obstruct the passage of air through the nose and throat. In some breeds, especially the Bulldog, this may be accompanied by narrowing of the trachea (wind pipe). Over time, the additional breathing effort that affected dogs take can lead to collapse of the larynx (‘voice box’). These abnormalities restrict the airway and reduce the space available for airflow. These dogs often exhibit noisy breathing, snoring and snorting sounds as a result of their increased respiratory rate.
In addition to trouble breathing, restrictions to the flow of air through the nostrils and internal nose structures can make it challenging for brachycephalic dogs to cool down, as the nose is the main area in a dog’s body where heat exchange occurs. This means that they are at high risk of overheating in warm weather, even in the UK, and you may often find your dog panting heavily.
Recurrent damage to the surface of the eye (the cornea) leading to corneal ulceration is common in extreme brachycephalic dogs, such as the Pug and English Bulldog. Although corneal ulcers can result from many causes, including injury and reduced tear production, corneal ulcers in brachycephalic dogs are commonly due to a variety of anatomical changes. These changes include a shallow eye with prominent, ‘bulging’ eyes, meaning many brachycephalic dogs cannot fully blink, which results in areas of cornea drying, especially in the centre of the eye. Many ‘flat faced’ dogs also have imperfect eyelid anatomy, as their eyelid opening is excessively wide, and their eyelids sometimes turn in (entropion) or out (ectropion). This can lead to further drying of the cornea, or damage due to contact with the eyelashes. In some dogs, the nasal fold comes into contact with the cornea, causing direct damage due to rubbing of the skin (or hairs on the skin) with the surface of the eye.
Chronic skin irritation and infection can be common in some extreme brachycephalic animals, specifically those with excessive wrinkling and skin folds, usually found on the muzzle (the nasal fold), but also around the tail and the vulva in female dogs, in association with screw-tails. Deep skin folds cause rubbing and retention of moisture, and may lead to overgrowth of bacteria and yeast. Local infections in these folds are common if they are not regularly cleaned.
Vertebrae are the linked bones that make up the backbone of the dog and protect the spinal cord, normally these are symmetrical and fit together with adjoining vertebrae. Some brachycephalic dogs, specifically those with coiled, very short or absent tails, are at an increased risk of abnormally shaped vertebrae that do not line up correctly; this can lead to instability of the spinal column, which in some dogs leads to the spinal cord or the nerves arising from it becoming compressed and damaged causing mobility issues and weakness.
Obesity is prevalent in the general canine population, affecting an estimated 20–40% of dogs. Many dogs with BOAS are overweight or obese, which may in part be due to their reduced ability to exercise normally due to difficulty breathing through their nose. This is problematic as a high body condition score is a risk factor for BOAS, and is associated with an increased severity of clinical signs.
This can be common in some brachycephalic breeds due to feto-pelvic disproportion; this is where selection for physical features, such as larger heads, results in puppies with heads too large to pass through the relatively narrow pelvises of the bitch without medical or surgical intervention.
Responsible ownership and breeding
Not all brachycephalic dogs will have the health issues described, but it is important that, if you are thinking of buying a puppy, you:
- Contact your local breed club for more information on the breed you’re considering.
- Research these health issues before purchasing a puppy, and be vigilant for signs of ill health so you can seek prompt veterinary advice.
- Buy from an assured breeder who adheres to good conformation standards www.assuredbreederscheme.org.uk.
- See the puppies with the mother, and where possible, the father as well.
- Make sure you ask the breeder about the health of the parents and ask to see any certificates for any health screening tests that the parents may have had.
1 O’Neill, D.G., Darwent, E.C., Church, D.B. & Brodbelt, D.C. (2016) Demography and health of Pugs under primary veterinary care in England, Canine Genetics and Epidemiology. Canine Genetics and Epidemiology, 3, 1- 12. Available at: https://link.springer.com/article/10.1186/s40575-016-0035-z
2 Kennel Club (2017) 10 Yearly Breed Statistics. Available at: https://www.thekennelclub.org.uk/media/129029/10yrstatsutility.pdf