Brachycephalic dogs

Brachycephalic dogs, or “Flatter-faced dogs” are becoming increasingly popular, with the Kennel Club reporting a 2,747 per cent rise in the number of French bulldogs registered since 2004. Unfortunately, a survey by the Royal Veterinary College found that 58 per cent of short-nosed dog owners did not recognise the signs that their brachycephalic dog was struggling to breathe.

We explain brachycephalic dogs, what to look for if you want to buy a flat-faced breed, and how to recognise when your dog may need vet help.

What does ‘brachycephalic’ mean?

The scientific word that vets use to describe short-nosed or flat-faced dogs is ‘brachycephalic’. This comes from two Greek words meaning ‘short’ and ‘head’.

Brachycephalic describes any dog whose muzzle looks like it has been flattened or squashed inwards. Their bottom jaw is disproportionately longer than their upper jaw, and the dog may look as though their lower jaw sticks out.

What breeds are brachycephalic?

Popular flat-faced breeds in the UK include French bulldogs, English bulldogs, Boston terriers, pugs, Cavalier King Charles spaniels, shih tzus and boxers.

These breeds’ looks tend to appeal to us because they look similar to human babies with their big ‘puppy dog’ eyes and make fun companions, so it’s no surprise that people want to add them to their families – but they do tend to suffer from more certain health problems than those of their species with longer snouts.

What are the health risks for flat-faced dogs?

Not all dogs that are short-nosed will suffer from health problems relating to breeding, but too many do. As these breeds grow in popularity, our Blue Cross veterinary hospital teams are treating more and more dogs of brachycephalic breeds who do have a wide variety of problems caused by breeding for a characteristic flat-face.

Breathing problems

Brachycephalic obstructive airway syndrome (BOAS) – also known as brachycephalic syndrome – is common in flat-faced dogs. The ability to breathe normally is commonly a struggle for dogs with this syndrome.

Four-year-old bulldog Frank was treated by our Merton animal hospital for painful ulcers on his eyeballs, skin and ear infections, and a partially blocked airway

There are a few reasons why this syndrome causes these dogs breathing difficulties:

  • Flat-faced dogs have shorter muzzle bones in their skulls than dogs that have retained their traditionally longer snouts, but often the soft tissue around the mouth, nose and throat hasn’t decreased is size. Because of this, there is comparatively more skin and other soft tissue around these areas, which means the airway becomes narrowed or partially blocked as the tissue squeezes into a smaller space.
  • The windpipe in brachycephalic dog breeds is often deformed and narrowed, so less oxygen can be taken in with each breath
  • Dogs cannot sweat and instead regulate their temperature largely through panting. Dogs with a traditional longer muzzle cool themselves down quickly by drawing in air over the large surface area of the tongue, but shorter nosed dogs cannot do this as efficiently. Because of this, brachycephalic dog breeds are more likely to overheat. Some are even killed by hot weather, particularly if they are overweight or older.
  • Nostrils are one of two ways a dog can take in oxygen; the other being through the mouth. Brachycephalic dogs are more likely to have narrowed nostrils – also known as stenotic nares – making inhaling more difficult.

Heart problems

Shortened and narrowed airways result in laboured breathing meaning that these dogs constantly struggle to cope with a lack of oxygen in the bloodstream.

This puts a strain on the dog’s heart and makes them more susceptible to secondary heart problems.

Pug Bertie being anaesthetised before having his mouth and teeth examined by a Blue Cross vet team

Tooth problems

Dog breeds have been selectively bred over many generations to meet certain characteristics, and those bred to have a shortened upper jaw still have the same number of teeth as those of their species with longer snouts (adult dogs have 42 teeth).

Because they have to fit these teeth into a much smaller area, their teeth can overlap, increasing the risk of decay and gum disease.

Nine-month-old French bulldog Boss on his fourth visit to our Blue Cross mobile clinic for skin problems

Skin and ear problems

The shape of their heads means that these dogs often have deep skin folds around their eyes and narrowed ear canals. These are poorly ventilated which tends to encourage yeast infections so these areas can become very sore.

Eye problems

Many of these dogs have prominent eyes so their tear film doesn’t spread properly and they are very vulnerable to injury.

They easily develop ulcers on the eye which can easily result in loss of an eye if untreated.

Mating and giving birth

High numbers of some brachycephalic breeds struggle to give birth naturally.

English and French bulldogs commonly need Caesarean sections when their pups are ready to be born because selective breeding has caused a mismatch between the puppies’ large heads and the mothers’ birth canal. Vets call this ‘dystocia due to foetal-pelvic disproportion’.

While some bulldogs are able to give birth naturally, 86 per cent of English bulldog puppies, and over 80 per cent of French bulldog puppies, are delivered by C-section in the UK (Evans and Adams, 2010).

Without assisted births, these bulldog mothers would likely die in pain during the birth and their offspring are unlikely to survive, too.

Caesareans are major operations for any dog, but the risk increases for dogs who suffer from brachycephalic-related breathing problems.

Neurological problems

Brachycephalic breeds can suffer from neurological (brain) problems because of their generally compressed skull shape.

Syringomyelia is the most common of these; this is a painful condition where cavities or cysts form in the spinal cord. It is most often seen in Cavalier King Charles spaniels.

Flat-faced dogs may suffer from additional health problems related to their respective breed.

How do I recognise my flat-nosed dog is unwell?

Signs of breathing difficulties are often thought to be normal for these flat-faced breeds to show. Sadly, these signs are not normal for the canine species and are a sign that a dog needs veterinary help.

  • Narrow nostrils – or stenotic nares: the dog’s nostrils will appear narrow or tight, possibly more closely resembling closed slits than a round, open nostril. Wheezing when inhaling is a common sound.
  • Overlong soft palate: this obstructs air getting into the windpipe and makes breathing a struggle. Dogs with this problem may make a snorting or grunting noise.
  • Narrow airway: obstructions in a dog’s airway can sound like snoring, coughing or gagging

Be wary of exercising flat-faced dogs too much in hot weather as they can quickly fall victim to heatstroke.

Book your pet an urgent vet appointment if you think they are having trouble breathing. You should also act promptly if they have a sore or discharging eye, or sore or smelly skin or ears.

Be aware that brachycephalic dogs:

  • are more likely to suffer from disturbed sleep
  • succumb to heatstroke more easily
  • become overweight quickly
  • can develop sore and painful joints
  • often suffer skin infections

Treatment for brachycephalic dogs with breathing difficulties

Brachycephalic breeds are at risk of breathing-related problems precisely because their head shape has changed so much from the healthier long-nosed muzzle shape that is a normal characteristic of the dog species. Without selectively breeding for a healthier skull conformation, these inherited problems cannot be prevented.

It is true that less exaggerated examples of flat-faced dogs breeds suffer less than those with more extreme features, and not all brachycephalic dogs will need veterinary intervention during their lifetime. The problem for these breeds is that too many of them do need surgery simply to be able to breathe normally.