Study reveals benefits of crossbreeding flat-faced dogs
Most puggles were found to be 'unaffected' by breathing difficulties.
Brachycephalic-cross dogs proved healthier than purebred flat-faced breeds.

A study has found that crossbreeding extreme brachycephalic pugs with non-brachycephalic dog breeds significantly improved the health of their offspring.
 
Researchers hope that these breeding strategies will improve the health and wellbeing of these dogs, while maintaining the behavioural traits which contribute to pugs’ popularity.
 
In the study, led by the Royal Veterinary College, the research team compared 150 UK-based pugs and pug-crossbreed dogs. These dogs were recruited between November 2023 and September 2024.
 
The dogs each had an in-person veterinary assessment, which examined them for respiratory, eye, dental, skin and neurological disorders. They also underwent a Respiratory Function Grading System (RFGS) assessment, which is used to grade the presence and severity of Brachycephalic Obstructive Airway Syndrome (BOAS), and a full body shape assessment.
 
Owners were given a questionnaire, which covered their dog’s health history, veterinary costs, exercise and maintenance requirements, behaviour, quality of life and owner-dog relationship.
 
Researchers discovered that there had been major improvements in the overall health of pug-crossbreed dogs when compared to purebred pugs.
 
All the purebred pugs in the study had affected breathing, with 47.1 per cent diagnosed with severe airway disease. Meanwhile, all the Jugs (Pug x Jack Russell terrier) and all but one puggle (Pug x Beagle) were graded as ‘unaffected’ by breathing difficulties.
 
This has been linked with the substantially longer relative muzzle length, which was observes on jugs and puggles. A longer relative muzzle length has been strongly associated with a lower risk of respiratory disease in statistical analyses.
 
Purebred pugs often displayed severe nostril narrowing, nasal skin folds and eye abnormalities, such as entropion and ectropion. They were also more likely to be reported by their owners to have breathing, heat regulation and exercise problems.
 
Jugs and puggles were less likely to have nasal skin folds, significantly less likely to display eye abnormalities, and displayed significantly fewer orthopaedic and neurological abnormalities.
 
Owners of jugs and puggles were also more likely to describe their dog’s quality of life as ‘excellent’ compared to purebred pugs.
 
Researchers believe that the dog-owner bond does not differ between pugs, jugs and puggles. However, there was an improvement in trainability among crossbreed dogs.
 
Elizabeth Youens, Master’s student at RVC and first author of the paper, said: “Our findings suggest that improving the welfare of brachycephalic dogs does not have to come at the expense of the qualities owners value most. The Jugs and Puggles in this study showed markedly better health outcomes than purebred Pugs while maintaining similar behaviour profiles and strong owner-dog relationships.
 
“Purposeful crossbreeding away from extreme body shapes is now shown as offering a practical route to improving canine welfare.”
 
The full study can be found in the journal Animal Welfare.

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