The gene responsible for causing breathing problems and wheezing in short-nosed dogs has been identified by scientists.
Future short-nosed dogs may not suffer with the chronic breathing problems they are infamous for as a result, they say.
Scientists have discovered a DNA mutation that could be behind their notorious wheezing.
The faulty gene is linked with fluid retention and causes the lining of the airways to swell.
Genetic tests looking at the ADAMTS3 gene could help vets identify animals at risk and help breeders avoid producing affected pups.
It has long been believed the desire of owners for squat skulls and a scrunched up face led to the problem, but this study casts doubt on that belief.
It is found in popular flat-nosed dog breeds such as French and English Bulldogs, pugs and the Norwich terrier, which has a proportional nose but suffers with the same issues.
The discovery means the shape of the breed’s skull may not be the only factor causing breathing hardship for dogs.
Many of the dogs with shortened noses are affected by a condition called Bracycephalic Obstructive Airway Syndrome, or BOAS.
This can often leave dogs gasping and short of breath.
Dr Jeffrey Schoenebeck and his team at the Roslin Institute at the University of Edinburgh’s Royal (Dick) School of Veterinary Studies analysed DNA from more than 400 Norwich terriers.
Vets also carried out clinical examinations of the dogs to check their airways for signs of disease.
The mutated version of the gene was also common in French and English bulldogs, which may help to explain why some dogs of these breeds develop breathing problems and complications after surgery to treat them.
Dr Schoenebeck said: ‘We conclude that there are additional genetic risk factors, that if inherited, will likely lead to airway disease in dogs regardless of their face shape.
‘The challenge ahead is to integrate these ideas, and implement sensible breeding practices and treatments that consider various health risks including those presented by the mutation of ADAMTS3. BOAS is a complex disease.
‘Although skull shape remains an important risk factor, our study suggests that the status of ADAMTS3 should be considered as well.
‘More studies are needed to dissect the complex nature of this devastating disease.’
Senior specialist surgeon Dr Jon Hall, who leads a specialist clinic for dogs with upper airway problems called BREATHE, said: ‘This discovery is a step change in our understanding of upper airway problems in dogs, which we hope will allow us to identify dogs at greater risk of catastrophic airway swelling before it happens.’
Along with helping dog breeders be safer in their practices, screening for the mutation may also help veterinarians identify dogs which are at risk of UAS, and in particular identify the dogs at risk of swelling of their airways after surgical treatment, which is a common, life-threatening post-operative complication.
The findings were published in the journal PLOS Genetics.