Why pugs and bulldogs have flat faces: Scientists pinpoint the mutation that causes squashed features
Study looked at DNA from 374 dogs of various pedigree and mixed breeds All of the animals underwent scans that produced 3D images of their heads This enabled researchers to take measurements of the shape of the dog’s skull
The team were able to pinpoint DNA variations associated with head shapes
It may shed light on the causes of birth defects that affect babies’ head development in the womb bulldogs have flat faces
With their squashed noses and wrinkled faces, they have become a favourite with dog lovers
Now, scientists believe they have uncovered a genetic mutation behind why some dogs – such as pugs and bulldogs – have flat faces.
The researchers hope it may also shed light on the causes of birth defects that affect babies’ head development in the womb. Vets are long warned against buying fashionable ‘flat-faced’ dogs amid concerns over their health and welfare.
The dogs, such as French bulldogs, pugs and Pekingese, are bred to emphasise certain ‘cute’ features which make them susceptible to a number of severe health problems, including difficulty breathing, infection and eye problems.
Researchers at the University of Edinburgh’s Roslin Institute wanted to find out exactly what causes these flat features.
They analysed DNA samples from 374 pet dogs of various pedigree and mixed breeds, that were being treated at the Royal (Dick) School of Veterinary Studies.
All of the animals underwent body scans as part of their care, producing detailed 3-dimensional images of the dogs’ heads.
These high-resolution images – called CT scans – enabled the researchers to take precise measurements of the shape of the dog’s skull.
By comparing the dogs’ genetic information with measurements of their skulls, the team were able to pinpoint DNA variations that are associated with different head shapes.
One variation – found to disrupt the activity of a gene called SMOC2 – was strongly linked to the length of the dog’s face.
Animals with the mutation had significantly flatter faces, a condition called brachycephaly.
Lead researcher Dr Jeffrey Schoenebeck, of the University’s Roslin Institute, said: ‘Our results shed light on the molecular nature of this type of skull form that is so common and popular among dogs.’
Babies are sometimes born with brachycephaly, but until now scientists had no answers as to why.
Now they reckon screening children for changes in the SMOC2 gene could help to diagnose the condition.