New research in New Zealand has shown what dogs and their ancestors have known for thousands of years - their bodies can process meat easier than other foods.
The study, led by AgResearch and Massey University, and only the second of its kind in the world, found a high-meat diet is easier for dogs to digest, enables more nutrients to be absorbed and resulted in higher levels of bacteria associated with protein and fat digestion.
The study's authors say higher levels of bacteria demonstrated a dog's gut is biologically designed to digest a diet high in meat.
They discovered this by analysing dog poo. The droppings of 15 adult dogs exclusively fed either a premium kibbled diet or a raw red-meat diet for nine weeks were analysed for apparent digestibility of macro-nutrients such as protein and fat, as well as being weighed and analysed.
"We already know dogs have no nutritional need for carbohydrates in their diet, so this study looked at the role different bacteria play in a dog's digestion system - to help us work toward a clearer picture of what the optimum diet is for dogs," says study co-lead Dr Emma Bermingham of AgResearch.
"Understanding how bacteria works in the gut is vital because of its links to digestion, diseases such as obesity, and even how it affects mood and behaviour."
In summary, the study found high-meat diets are more digestible for dogs; more nutrients from a high-meat diet were able to be absorbed and dogs on a high meat diet had higher levels of the gut bacteria associated with protein and fat digestion.
Also, dogs on a high meat-diet had smaller droppings and better faecal health - a blessing for anyone who regularly picks up after their pet, as all responsible owners should.
Study co-lead Associate Professor David Thomas, of Massey University, says finding high levels of bacteria associated with protein and fat digestion was particularly exciting, as it demonstrated a dog's gut is biologically designed to digest high-meat diets.
"Up until now science has looked at studies on nutrient digestion in human, mice and rats and assumed the same is true for dogs in terms of digestion and what is good and bad bacteria in the gut.
"This study shows this may not the case and much more needs to be done to understand the digestive system of dogs and the long-term health consequences of different diets."
The study was co-funded by the Ministry of Business, Innovation and Employment through the Outcomes for Science Targeted Research Fund and the New Zealand Premium Petfood Alliance - a collaboration between leading pet-food manufacturers Bombay Petfoods (manufacturers of the Jimbo's brand), K9 Natural and ZiwiPeak.
Sam Boston, pet adviser for Bombay Petfoods, says the findings underline what the company has intuitively known for years.
"While we get used to dogs living in our homes, they are descended from wild animals whose diet consisted mostly of meat, though they naturally eat plant-based food as well." Boston says. "This study supports our long-held view that dogs need to be fed a high-meat, low-carbohydrate diet best suited to their biological makeup."
Boston is pleased that Massey and AgResearch have undertaken the study, which will make a significant contribution to the international animal nutrition field.
"Most if not all pet-owners want the best for their animal and will be interested to hear about these new findings. A lot of diets on the market have been designed to ensure a dog survives but this research shows that high-meat diets help a dog thrive."
The next full study from the research programme, on the effects of feeding cats a high-meat diet, is due for completion mid-year.