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.
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.
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.
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.
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.
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.
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.
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.