Listen: Professor Paul McGreevy in Conversation with Stephen O’Doherty.
New research led by the University of Sydney, has revealed the life expectancy of chocolate Labradors is significantly lower than their black and yellow counterparts.
Lead author Paul McGreevy, Professor of Animal Behaviour and Animal Welfare Science from the University of Sydney Faculty of Science, says the relationship between coat colour and disease came as a surprise to researchers. The UK findings may not hold in Australian Labradors, he says, but warrant investigation.
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. The findings were just published in the open access journal Canine Genetics and Epidemiology .
Based on vet records
The article, ‘Labrador retrievers under primary veterinary care in the UK; demography, mortality and disorders’ was based on vet health records of 33,320 Labradors. The vet records provided a big database from which Professor McGreevey and his colleagues could get accurate information about Labrador health.
Labrador retrievers are reportedly predisposed to many disorders but accurate prevalence information relating to the general population has been scarce. The study aimed to put some hard numbers to anecdotal evidence.
Popular family dog
With origins in the game hunting fields of Canada and developed in the UK from the 1830s, the Labrador retriever is now firmly established as one of the most globally popular dog breeds and a leading family dog.
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Labradors were the most commonly registered UK pedigree dog breed in 2016–2017. The UK Kennel Club currently registers three colourings: black, chocolate, or yellow [ranging from pale yellow (nearly white) to fox red].
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.
The data collected for the study showed the females were more likely to be neutered than males. The most common recorded colours were black (44.6%), yellow (27.8%) and liver/chocolate (23.8%).
The median life-span of Labrador retrievers overall was 12 years but was much shorter in chocolate dogs. The most common causes of death were musculoskeletal disorders and cancer.
Obesity, joint conditions
The most common disorders affecting Labrador retrievers were overweight/obesity, ear and joint conditions. Skin and ear disease were significantly more common in chocolate dogs than in black or yellow dogs.
“We found that 8.8 percent of UK Labradors are overweight or obese, one of the highest percentages among dog breeds in the VetCompass™ database,” Professor McGreevy says.
The average adult bodyweight was 33 kg. Males were significantly heavier than females. The study also found a link between neutered male dogs and obesity. A previous study by Professor McGreevy investigated questions about behaviour and the age male dogs were neutered. That leads to some complicated questions for owners about when male dogs should be de-sexed.
Labs love to swim
Descended from dogs that were selectively bred to help fishermen retrieve nets and lost lines and then bred to retrieve fallen water-fowl and other game, the breed is known for engaging in swimming. This is important because regular swimming may increase the risk of ear inflammation (otitis externa). Additionally, unless the dogs are well-dried, may lead to increased humidity in the hair-coat that may increase the prevalence of skin disorders.
Chocolate Labrador health
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).
“The relationships between coat colour and disease may reflect an inadvertent consequence of breeding certain pigmentations,” says Professor McGreevy
It’s about genes
“Because chocolate colour is recessive in dogs, the gene for this colour must be present in both parents for their puppies to be chocolate. Breeders targeting this colour may therefore be more likely to breed only Labradors carrying the chocolate coat gene. It may be that the resulting reduced gene pool includes a higher proportion of genes conducive to ear and skin conditions.” he says.
Choosing a dog
Professor McGreevy specialises in animal behaviour and told Open House that the expressive mobile faces of horses make it easy to be a horse whisperer. The challenge is for people to learn to read the expressions and behaviour of dogs. He is also the co-author of the book Making Dogs Happy.
The study can help breeders and veterinarians tackle health issues in Labrador retrievers. The results can also alert prospective owners to potential health issues and inform breed-specific wellness checks.
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