The study of more than 33,000 United Kingdom-based Labrador retrievers of all colours shows chocolate Labradors also have a higher incidence of ear infections and skin disease. Its findings were published in the open access journal Canine Genetics and Epidemiology today.

Part of the University’s VetCompass™ Programme, which collects and analyses electronic patient data on dogs, the research is being replicated in Australia, where Labradors are the most popular breed of dog.

In the UK, the median longevity of non-chocolate Labradors is 12.1 years, more than 10 percent longer than those with chocolate coats. The prevalence of ear inflammation (otitis externa) was twice as high in chocolate Labradors, who were four times more likely to have suffered from pyo-traumatic dermatitis (also known as hot-spot).

Lead author Professor Paul McGreevy, from the University’s Faculty of Science, said the relationship between coat colour and disease came as a surprise to researchers. The UK findings may not hold in Australian Labradors, he said, but warrant investigation.