Understanding flat-faced breeds: Why anatomy matters

The term “brachycephaly” comes from two Greek words: brachy, meaning “short,” and cephalic, meaning “head.” The hallmark of brachycephalic dog breeds is their distinctive flat-faced appearance, with big round eyes, wrinkled foreheads and short snuffly noses. Pugs, Boston Terriers, French Bulldogs and Shih Tzus are examples of the breed type. Unfortunately, this unique conformation (anatomical structure) predisposes these popular pets to several health issues that can significantly and negatively impact their quality of life

Breathing Difficulties

One of the most critical health issues in flat-faced dogs is Brachycephalic Obstructive Airway Syndrome (BOAS). This condition stems from anatomical abnormalities of the skull and neck, with affected dogs often having small, narrowed nostrils, constricted airways, increased soft palate length and/or increased thickness of the soft tissues of the throat. This, in turn, leads to restricted airflow causing many of the common clinical symptoms and, in extreme cases, collapse of the larynx and stomach herniation (hiatal hernia)¹.

According to 2024 PetSure claims data, the average cost to treat BOAS is $3,174, with a maximum cost of $29,775 claimed during 2024. In addition, brachycephalic dogs represented 93% of all BOAS claims assessed during the year.

Brachycephalic breeds are also twice as likely to suffer from heat-related illnesses, ranging from heat stress through to heatstroke. Certain breeds, such as the English Bulldog, are 14 times more at risk of this, according to a research paper from the Royal Veterinary College in the UK².

Common symptoms of respiratory difficulties (due to the decreased ability to get adequate air into the lungs) include noisy breathing, snoring, wheezing, open mouth breathing, exercise intolerance, snorting, regurgitation, gagging, choking, abdominal breathing and fainting. Surgery to correct BOAS improves breathing ability and reduces exercise intolerance and secondary gastrointestinal diseases, but it comes at increased anaesthetic risk due to the existing compromised respiratory system. Many airlines also have travel restrictions in place for brachycephalic dogs, particularly in the United States, as altitude can worsen respiratory issues.

BOAS requires comprehensive management, which may include surgery if indicated, maintaining or achieving an ideal body weight, avoiding heat-related illness, and promoting responsible breeding. This includes both genetic and physical screening, where appropriate, to avoid breeding from susceptible dogs.

Anaesthesia and sedation concerns

The increasing popularity of flat-faced dog breeds has made sedating and anaesthetising them a common challenge in veterinary practice. Both vets and pet parents need to understand the risks involved. These dogs often have airway issues and data shows that many brachycephalic dogs undergoing surgery for BOAS have complications, such as abnormal breathing (stertor or stridor), gastrointestinal symptoms, and a history of previous BOAS surgeries³. This data also revealed 7% of these patients had major post-operative complications that required the placement of a breathing tube and/or resulted in death or euthanasia. The most important considerations are the likelihood of upper airway obstruction, poor oxygenation, impaired anaesthetic uptake and ventilation, risk of regurgitation and aspiration pneumonia, rocky post-operative recoveries and increased risk of post-op inflammation⁴.

Skin concerns

Breeding dogs for flat faces and curly tails has led to deep facial wrinkles and skin folds, making these dogs particularly susceptible to infection, such as skin fold dermatitis (or intertrigo) around the face and tail5. These infections occur due to the decreased air circulation around the excess skin folds and flaps, which creates a moist environment that fosters bacterial and fungal growth. Brachycephalic dogs are also predisposed to various additional skin concerns, including allergies (atopic dermatitis), demodicosis (a type of mange), pattern baldness and Malassezia dermatitis (a yeast infection). In addition, they are noted to be at increased risk of developing mast cell tumours and hair follicle inflammation and infections, particularly around the muzzle and paws6. Specific breeds have further unique problems, such as ear issues (primary secretory otitis media) in Cavalier King Charles Spaniels and hair loss (flank alopecia) in English Bulldogs and Boxers³.

PetSure 2024 claims data shows that brachycephalic breeds were almost twice as likely to suffer from skin allergies than non-flat faced breeds, with a prevalence of 19.4% and 10.4% respectively. The average cost to treat skin allergy was $815, with a maximum amount of $16,935. In 2024, brachy breeds were also found to have suffered 43% more from dermatitis and 24% more from skin conditions overall than their long-nosed counterparts.

Many of the skin issues faced by flat-faced dog breeds require long-term care and may involve multiple treatment modalities. This includes treatments such as:

• Medication that might be applied topically to the skin as well as taken internally to treat bacterial or yeast infections.

• Surgery to manage skin fold issues around the face and tail (intertrigo) or to remove cysts (pedal furunculosis) between their paw pads.

• Allergen-specific immunotherapy.

Dogs with atopic dermatitis (skin allergy) often have lesions on their ears, elbows and muzzle, which can be complicated by secondary infections. Updated treatment guidelines recommend a mix of therapies. Malassezia dermatitis, common in areas such as paws and ear canals, causes itching, inflammation, and greasy skin. This commonly requires medication to treat the whole body (systemic treatment) generally in the form of tablets or injections, as well as medication applied to particular areas of the body (topical treatments), such as creams or medicated washes. Demodex mites – normally harmless – can cause problems if the dog’s immune system is weak, leading to further inflammation and infection.

A diligent parasite preventative treatment (particularly for demodex mites if your dog is immunocompromised or has a history of demodex infestation), regular cleaning and avoiding hot, humid temperatures are fundamental to minimising the risk of developing some of these skin conditions.

Eye issues

The short, flat snouts of brachycephalic breeds lead to large, protuberant eyes that, while appealing to humans, are more susceptible to injury. This increases the risk of developing a range of eye problems collectively known as Brachycephalic Ocular Syndrome (BOS)⁷. This list includes corneal ulcers (damage to the surface of the eye), pigmentary keratitis and chronic dry eye. Often this is linked to a condition known as lagophthalmos, which means that affected dogs have difficulty fully closing their eyelids. This leaves their eyes vulnerable to ulceration, which can lead to scarring, eye perforation, or even blindness if left untreated.

In one study of 700 dogs, 31 developed corneal ulcers, with Pugs being the most affected breed8 .The same study found that brachycephalic dogs were 20 times more likely to develop corneal ulcers compared to other breeds and dogs with a wider gap between their eyelids (a trait encouraged by breed standards) were more than three times as likely to get corneal ulcers. Other factors included visible sclera (whites of the eyes), which was associated with almost three times the rate of corneal ulcers, while dogs with nasal folds were five times more likely to suffer from the same condition. Additionally, long or curved eyelashes and hairs near the eyes can cause further harm and irritation to the surface of the eye. Treatment, whether surgical or medical, is often necessary depending on the cause and severity of the eye condition.

PetSure claims data in 2024 shows that brachycephalic dogs were more than six times more likely to claim for corneal ulceration than non-brachy breeds, with a prevalence of 3.6% instead of 0.5% in the non-flat faced dog population. Furthermore, the average cost to treat corneal ulceration in brachy breeds in 2024 was $1,100 with a maximum claim amount of $19,420.

Dental and gastrointestinal problems

Brachycephalic dogs have the same number of teeth as other breeds, but their shorter, wider skull means those teeth have less space to fit into. As a result, they often become overcrowded, which can cause teeth to overlap or rotate, increasing the risk of gum infections from the build-up of bacteria. Additionally, many brachycephalic dogs have an underbite, where the lower jaw is longer than the upper jaw. In severe cases, these dental issues can make eating challenging and potentially lead to other health problems.

Brachycephalic dogs are prone to swallowing excess air, and due to their narrowed airways and other inherited abnormalities, these dogs must exert extreme effort to expand their chests and increase airflow into their lungs. In turn, this can cause stomach contents, or even the stomach itself, to be sucked through the diaphragm into the chest cavity (hiatal hernia). This can then lead to vomiting, regurgitation, and irritation of the oesophagus from acidic stomach contents, resulting in discomfort and heartburn. Additionally, food can remain in the stomach for extended periods, creating a sensation of nausea and further raising the likelihood of vomiting and acid reflux.

PetSure claims data 2024 reflects this increased risk, with brachycephalic dogs 20 times more likely to require treatment for hiatal or diaphragmatic hernias than non-brachycephalic dogs at an average cost of $5,030.

Studies have also shown that a significant number of brachycephalic dogs experience abnormal reflux, which can be measured by analysing the acidity levels in the throat⁹. Managing this condition often involves dietary adjustments and, in some cases, medical treatment.

Ethical considerations, breeding and veterinary strategies

The increasing popularity of brachycephalic breeds has raised ethical concerns regarding their breeding and welfare. In addition to the concerns already noted, many flat-faced dog breeds often have trouble giving birth naturally. This is mainly because the puppies have skulls that are too large for the birth canal. As a result, more than 85% of bulldogs in the UK are born by caesarean section¹⁰.

Veterinarians emphasise the importance of responsible breeding practices to reduce the prevalence of conformation-related health issues. Some vets advocate to stop breeding these dogs completely due to welfare concerns. Strategies for managing and preventing these disorders include selecting breeding pairs with less extreme features, educating breeders and owners about the risks, and advocating for changes in breed standards.

Aside from the ethical concerns, veterinarians face unique challenges when treating brachycephalic dogs, especially during anaesthesia and surgery. These breeds are at higher risk of complications before, during and after the operation due to airway obstruction, stress-related issues, and aspiration pneumonia. To mitigate these risks, veterinarians often use pre-medication to reduce stress, carefully monitor anaesthesia, and employ advanced techniques to maintain open airways. Owners should do their best to ensure their pets are in good health, which includes weight loss if needed before any surgical procedures, and follow individual veterinary advice closely.

Prevention and management strategies

To help manage and prevent health issues in brachycephalic dogs, pet parents can take several proactive steps:

1. Exercise with Care: All dogs need exercise, but careful moderation is necessary for these pets to avoid overexertion, overheating and breathing difficulties. It’s always best to exercise them in the cooler parts of the day (ideally first thing in the morning) with water readily available at all times.
2. Weight Management: Maintaining an ideal body weight reduces the strain on a compromised respiratory system, may also reduce skin folds and contribute to overall health.
3. Regular Veterinary Check-ups: Frequent visits to the vet can help detect and manage health issues early.
4. Avoiding Heat Stress: Brachycephalic dogs are prone to overheating, so it’s crucial to keep them cool and avoid strenuous exercise, particularly in hot weather.
5. Proper Grooming: Regular, appropriate cleaning of skin folds and eye care can prevent infections and other complications.
6. Use of Harnesses: Using a harness instead of a collar can help reduce pressure on the neck and airways.

Owning a brachycephalic dog comes with unique challenges, but with proper care and awareness, many of these health issues can be managed. Regular veterinary visits, preventive care, and informed breeding practices are key to ensuring the wellbeing of these beloved pets. By understanding the risks and taking proactive measures, pet parents can help their brachycephalic dogs lead healthier, happier lives.

---

References

1. Mitze S, Barrs VR, Beatty JA, Hobi S, Bęczkowski PM. Brachycephalic obstructive airway syndrome: much more than a surgical problem. Vet Q. 2022 Dec;42(1):213-223. doi: 10.1080/01652176.2022.2145621. PMID: 36342210; PMCID: PMC9673814.
2. Hall, E.J., Carter, A.J. & O’Neill, D.G. Incidence and risk factors for heat-related illness
   (heatstroke) in UK dogs under primary veterinary care in 2016. Sci Rep 10, 9128 (2020). https://doi.org/10.1038/s41598-020-66015-8
3. Ree, J.J.; Milovancev, M.; MacIntyre, L.A.; Townsend, K.L. Factors associated with major complications in the short-term postoperative period in dogs undergoing surgery for brachycephalic airway syndrome. Can. Vet. J. 2016, 57, 976–980.
4. Fawcett A, Barrs V, Awad M, Child G, Brunel L, Mooney E, Martinez-Taboada F, McDonald B, McGreevy P. Consequences and Management of Canine Brachycephaly in Veterinary Practice: Perspectives from Australian Veterinarians and Veterinary Specialists. Animals (Basel). 2018 Dec 21;9(1):3. doi: 10.3390/ani9010003. PMID: 30577619; PMCID: PMC6356869.
5. Hobi S, Barrs VR, Bęczkowski PM. Dermatological Problems of Brachycephalic Dogs. Animals (Basel). 2023 Jun 16;13(12):2016. doi: 10.3390/ani13122016. PMID: 37370526; PMCID: PMC10294810.
6. Miller, W.H.; Griffin, C.E.; Campbell, K.L. Muller and Kirk’s Small Animal Dermatology, 7th ed.; Elsevier Mosby: St Louis, MO, USA, 2013.
7. Sebbag L, Sanchez RF. The pandemic of ocular surface disease in brachycephalic dogs: The brachycephalic ocular syndrome. Vet Ophthalmol. 2023 Apr;26 Suppl 1:31-46. doi: 10.1111/vop.13054. Epub 2022 Dec 31. PMID: 36585820.
8. Packer, R.M.A.; Hendricks, A.; Burn, C.C. Impact of facial conformation on canine health: Corneal ulceration. PLoS ONE 2015, 10, e0123827
9. Appelgrein C, Hosgood G, Thompson M, Coiacetto F. Quantification of gastroesophageal regurgitation in brachycephalic dogs. J Vet Intern Med. 2022 May;36(3):927-934. doi: 10.1111/jvim.16400. Epub 2022 Apr 7. PMID: 35388526; PMCID: PMC9151495.
10. Ekenstedt, K. J., Crosse, K. R., & Risselada, M. (2020). Canine brachycephaly: Anatomy, pathology, genetics and welfare. Journal of Comparative Pathology, 176, 109–115. https://doi.org/10.1016/j.jcpa.2020.02.008

Additional supporting references

• https://www.vetvoice.com.au/campaigns/love-is-blind/
• https://www.vin.com/apputil/content/defaultadv1.aspx?pId=22915&id=8896661)
• https://healthtopics.vetmed.ucdavis.edu/health-topics/brachycephalic-short-nosed-dogs
• https://www.aaha.org/trends-magazine/publications/anesthetic-considerations-for-brachycephalic-dog-breeds/
• https://www.rvc.ac.uk/research/focus/brachycephaly/health-issues
• Understanding Brachycephalic Dog Breeds: Health Concerns and Care Tips (https://broomfieldvet.com/blog/brachycephalic-dog-breeds/
• https://broomfieldvet.com/blog/brachycephalic-dog-breeds/
• https://vetscienceweek.com.au/Microsite/pdf/full-paper_272.pdf
• https://www.mspca.org/angell_services/caring-for-brachycephalic-dogs/
• http://Addressing brachycephalic obstructive airway syndrome (BOAS) in general practice