You Are What You Eat! And that's the same for your dog!
We all know the expression: ‘You are What you Eat’, but how often do we think about how food is processed in our bodies to be metabolised into cellular energy?
It’s a process that’s critical for survival in all species and it relies on digestion, absorption and elimination along with the gastrointestinal tract doing its job by being in the best functioning condition.
It involves the clever biological and physiological interplay of several organs, along with the help of many enzymes and secretions to make this miraculous conversion of food into cellular energy.
Whilst there’s many physiological similarities between a dog’s digestive system and a human’s, there’s also some key biological differences, which could influence our dietary choices for dogs to promote optimum health.
In summary, digestion begins in the mouth using teeth to chew and create saliva before being swallowed into the esophagus where muscular contractions deliver the food particles into the stomach.
This is where digestive acids and enzymes churn the contents, breaking it all down, before reaching the small intestine, which is where the majority of nutrient absorption tales place.
The small intestine contains finger-like villi that absorb nutrients that have been broken down: minerals, vitamins, amino acids, fatty acids and simple sugars. The gallbladder and the pancreas secrete enzymes for fat, protein and carbohydrate breakdown. Finally in the large intestine waste products and water accumulate, which then hopefully end up in a bio-degradable poop bag!
Interestingly, if digestion begins in the mouth, there lies possibly the biggest difference between dogs and humans. Apart from very physically different dental structures, dogs’ being designed to slash and grab meat, dogs have 42 teeth and compared to our 32.
A major difference is that 50% of human saliva contains salivary amylase, which is a protein enzyme specifically designed to rapidly alter the physical properties of starch. Dogs naturally don’t produce this starch digesting enzyme in their saliva at all!
This suggests that complex carbohydrates like rice, potatoes, sweet potatoes, legumes, and grains are more difficult, if not impossible, for dogs to digest’, whereas in people it indicates we’re adept at eating starchy foods. In fact, humans are the only species to produce saliva amylase in such an amount. Even Chimpanzees our closest relative produces little or none!
Adding to the important differences between dogs and humans, its notable that a dog’s stomach pH is dramatically different from ours!
Dogs are likely to produce up to 100 times the amount of acid than a human stomach. This means dogs rapidly break down proteins and have no problems softening bone matter or grizzly bits that would be impossible for a human to digest.
Additionally, the enzyme secretion from the pancreas into the small intestine (at a critical phase of digestion) is quite different. The Pancreas produces three main enzymes: Amylase to break down single carbohydrates, Protease to break down proteins and Lipase (from the gall bladder) to break down fats.
Herbivores and humans both have a mildly acidic stomach pH between 4 and 5 when food is present, whereas carnivores have a far more acid stomach pH of 1 or less when digesting food.
Whilst dogs do similarly produce a comparatively small amount of Amylase to breakdown single carbohydrates, the amount of Protease secreted in a canine’s pancreas is significantly higher than in a human’s. Plus, a carnivore does not secrete cellulase, unlike in a ruminant like a cow, to split cellulose into glucose molecules.
Dog’s digestive tracts are shorter than humans' at approximately two metres compared to a human’s nine metres! Typical of all carnivores, being predisposed to eat raw meat, which is digested faster in an acidic and short digestive tract as being easily bio-available. In contrast to a dog’s inability to digest starchy foods.
The health concerns around consuming overly processed, sterile, even overly cooked foods on a regular basis can result in less-than-optimal enzyme production and metabolic function overtime. In contrast to an abundance of enzymes available in fresh, raw meats, offal and bone.
Sadly, the depletion of natural sources of enzymes can lead to health issues, even premature ageing. Many conditions, including, pancreatitis, diabetes, and irritable bowel disease, skin conditions, arthritis, periodontal disease, yeast build up, hyper sensitive behaviour can be attributed to a diet that a dog simply isn’t born to eat.
Recent studies on the Microbiome (situated in the lining of the small intestine) relies on bacteria both good and bad to thrive as an independent eco-system. This is where the immune system resides and its where the clever relationship known as the gut / brain axis should flourish.
As research highlights the link between cognitive function and the digestive system, surely, it’s time to ‘paws’ for thought, and think that dogs thrive on species appropriate foods that are fresh and whole!