Chocolate, Yellow, and Black Labrador Retrievers (image)
The University of Sydney, in collaboration with the Royal Veterinary College at the University of London, recently published research in the Journal of Canine Genetics and Epidemiology which reveals that canine color may have an impact on disease, ailments, and even lifespan of man's best friend.
The study was conducted on data from a sample of more than 33,000 Labrador Retriever veterinary records during the year 2013. It compared a variety of factors, including weight, disease, and death records for Labradors by color, specifically, yellow, black, and chocolate retrievers. The proportion of dogs represented in the study by color was: black (44.6%), yellow (27.8%), and chocolate (23.8%).
Chocolate Labrador puppy (image)
Although chocolate labs were prone to the same health conditions as black and yellow labs (e.g., otitis externa, overweight/obesity, pyo-traumatic dermatitis, and degenerative joint disease), some of these conditions were more prevalent in chocolate labs than in yellow or black labs. The most common causes of death among chocolate labs were musculoskeletal disorders and cancers.
The median longevity of non-chocolate colored dogs was 12.1 years, while the chocolate labs median longevity was 10.7 years.
The greater prevalence of disease among chocolate labs, along with a significantly lower life span, led the researchers to conclude that color might be a factor in the occurrence of disease and early death, not just in Labradors, but in other dogs as well.
Chocolate (or 'liver') is a recessive color gene in labs. Therefore, both male and female labs must be chocolate color in order to have chocolate puppies. One possible theory is that chocolate labs are more prone to disease and early death because the gene pool of chocolate labs may be more limited than if chocolate gene was dominant.
In The Future
The University of Sydney will duplicate the study with Labradors in Australia to see if the results are similar. Then, the researchers plan to see if color is an important factor in studying the health and life span of other breeds.
Origins of the Labrador Retriever
Labrador Retrievers originated in Newfoundland, Canada during the 1800's, and are believed to be descendant from the Newfoundland Dog and the St. Johns Dog.
St John's Dog (image)
The St. John's Dog is now extinct, but you can see from the above photos, that labs have a strong resemblance to both the Newfoundland and the St. Johns Dog. The St. Johns Dog surely contributed his love of water to the Labrador; he was also known as "St. Johns Water Dog."
According to DogAppy:
"During the period of colonization, in the 19th century, the Labradors came to England and then moved across rest of the European countries. People used this dog breed as retrievers. They would accompany their masters on a hunting trip and when a bird was shot, these dogs went and retrieved the hunt for their masters, thus the name 'retrievers'. The origins of the chocolate labs can be traced back to 8 original bloodlines. But it was only in the 20th century that this color was seen as a distinct color."