New genes are needed, experts warn
THE BRITISH bulldog, symbol of Churchillian courage and perseverance, is at risk of being defeated by its unhealthy genes, experts have warned.
Scientists say the breed cannot continue in its pure form without causing the animals necessary suffering.
They believe an infusion of new genes is needed to improve the future fitness of the British bulldog, also known as the English bulldog.
New research suggests it will be difficult to improve the health of the British bulldog from within its existing gene pool.
Selective breeding for specific traits has caused large regions of the bulldog’s genome, or genetic code, to be altered, leading to extreme changes in appearance. As a result, it is one of the world’s unhealthiest dog breeds.
British bulldogs suffer a wide range of health problems, including skin infections, abnormal teeth, difficulty breathing and eating, heat sensitivity, malformed hip joints, and spinal deformity.
Even so, the dog remains highly sought after, especially in the US where it was the fourth most popular pure breed in 2015.
Dr Niels Pedersen, from the Centre for Companion Animal Health at the University of California, Davis, who led the new study published in the journal Canine Genetics And Epidemiology, said: “The English bulldog has reached the point where popularity can no longer excuse the health problems that the average bulldog endures in its often brief lifetime.
“More people seemed to be enamoured with its appearance than concerned about its health. Improving health through genetic manipulations presumes that enough diversity still exists to improve the breed from within, and if not, to add diversity by out-crossing to other breeds. We found little genetic ‘wiggle room’ still exists in the breed to make additional genetic changes.”
Changes to the genome of the dog and its ancestors had taken place over hundreds of years, but had gained pace over the last few decades, he pointed out.
Breeding out all the mutations linked to ill-health was not the answer, as this would further reduce genetic diversity.
“We would also question whether further modifications, such as rapidly introducing new rare coat colours, making the body smaller and more compact and adding more wrinkles in the coat, could improve the bulldog’s already fragile genetic diversity,” Dr Pedersen added.
The scientists looked at 102 British bulldogs – 87 from the US and 15 from other countries. Their DNA was compared with that of another 37 British bulldogs brought to the US Davis Veterinary Clinical Services for health problems.
Breeders in Switzerland have started to out-cross the British bulldog with the Olde English Bulldogge – paradoxically, an American breed.
The resulting Continental Bulldog is an attempt to improve the animal’s health, said the researchers. But many breeders were opposed to any reduction of the British Bulldog’s purity.
Several bulldog breeds exist today. The original Old English Bulldog is now extinct. It was a compact, muscular animal with vice-like jaws, bred for bull-baiting. When bull-baiting was banned in 1835, the Old English Bulldog was crossed with the pug to produce a shorter, wider dog with a characteristically flat snout.
Popularity can no longer excuse the health problems it endures. Dr Niels Pedersen