Learning about our dogs digestive needs :
Genetically, the dog, Canis Lupus Familiaris, is closely related to wolves,Canis Lupus.
Dogs are so much like wolves physiologically that they are frequently used in wolf studies as a physiological model for wolf body processes. (Mech, L.D. 2003. Wolves: Behavior, Ecology, and Conservation).
Additionally, dogs and wolves share 99.8% of their mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is theDNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, adenosine triphosphate (ATP). (Wayne, R.K. Molecular Evolution of the Dog Family).
When we compare digestive physiology between a carnivore, omnivore, and herbivore we find very distinct differences, Carnivores digestive systems are 3-6 times their body length, their guts are short, smooth, and fast acting to digest proteins quickly. Omnivore’s digestive systems are 6 times their body length, while herbivores are about 30 times their body length because fibre requires longer digestion to break down cellulose. Livers in carnivores are larger to process proteins and nitrogenous wastes, they also have an highly elastic stomach designed to hold large quantities of meat, bone, organs, and hide. Carnivores stomachs are simple, with an undeveloped caecum
(Feldhamer, G.A. 1999. Mammology: Adaptation, Diversity, and Ecology. McGraw-Hill. pg 260.).
They have a relatively short foregut and a short, smooth, unsacculated colon. This means food passes through quickly. Vegetable and plant matter, however, needs time to sit and ferment. This equates to requiring longer, sacculated colons, larger and longer small intestines, and occasionally the presence of a caecum. Dogs have none of these, but have the shorter foregut and hindgut consistent with carnivorous animals. This explains why plant matter comes out the same way it came in; there was no time for it to be broken down and digested (among other things). Some educated People know this; this is why they tell you that vegetables and grains have to be pre-processed for your dog to get anything out of them. But even then, feeding vegetables and grains to a carnivorous animal is a highly questionable practice.
“Dogs do NOT normally produce the necessary enzymes in their saliva (amylase, for example) to start the break-down process of carbohydrates and starches; amylase in saliva is something omnivorous and herbivorous animals possess, but not carnivorous animals. This places the burden entirely on the pancreas, forcing it to produce large amounts of amylase to deal with the starch, cellulose, and carbohydrates in plant matter. The carnivore’s pancreas does not secrete cellulase to split the cellulose into glucose molecules, nor have dogs become efficient at digesting and assimilating and utilizing plant material as a source of high quality protein. Herbivores do those sorts of things” Canine and Feline Nutrition Case, Carey and Hirakawa Published by Mosby, 1995
Over the years, through breeding, humans have developed different breeds and have shaped dogs to live in our lifestyle. The dog has become dependent on us for survival (Mech, 1991). Although dogs look different than wolves, they have the same number and shape of teeth (42) indicative of tearing and shredding meat (Coppinger and Coppinger, 2001). Characteristics of a carnivores teeth are sharp and jagged, unlike an herbivore whose molars are flat to break up vegetable matter. Carnivore’s jaws are hinged to be able to consume large pieces of meat where herbivores jaws grind sideways to break up their food (Olsen, 2010). Dogs, as well as cats, still retain their carnivorous features. They still have teeth and claws designed to catch, rip, and tear meat. Their eye position is still forward on their skull to focus on prey animals, whereas, their prey have eyes set to the sides of their skulls to watch for attacks (Schultz, 1998). The internal workings and physiology did not change in the domestication process of dogs. Although we changed their appearance and mind, we did not change their requirement for food and exercise (Baker, 2002). For thousands of years the domesticated dog survived on whatever food was available. There was no one to make sure their diet was balanced, complete and free from bacteria.
They lived in a biologically appropriate environment. In the wild, a wolf’s diet consists of bones and meat, organs, decaying material, and partially digested vegetable matter in a raw food state. They even eat faeces (Billinghurst, n.d.). According to Billinghurst (n.d.), “Wolves actually obtain healthy bowel bacteria along with proteins, fatty acids, vitamins, and fibre through faeces.” A species natural food is biologically adapted to their heritage from thousands of years ago. Dogs are scavengers and have lived in a world of bacteria and germs for thousands of years. They have eaten dead animals and carrion and have thrived through generations of dogs. Our dogs like to bury bones and objects in the ground to be dug up later and chewed on. That bone is contaminated with bacteria in a number that’s incomprehensible. Food in the stomach of a carnivore gets a repeated bath of hydrochloric acid. The low pH provides a barrier to pathogens. Small amounts of food are then released by the pyloric sphincter into the duodenum where the pancreas secretes peptides, called defensins, that inhibit and kill any pathogens (Brown and Taylor, n.d).
To achieve all the nutrient requirements for a dog, a raw food diet should consist of:
Raw meat – muscle meat from chicken, beef, turkey, fish, lamb, rabbit etc. Organ meat is all the internal organs.
Raw bone, included with the muscle meat. Rib bones for chewing, but weight bearing bones of older animals are too dense and can damage teeth or worse cause blockages , Generally 80% meat 10% bone & 10% offal
For raw feeders that do give vegetables to their dogs, such as
(asparagus, broccoli, celery, lettuce, kale, squash, carrots, green beans) they are high in oxalic acid and should be fed sparingly as it may interfere with calcium absorption. Too many of these cruciferous vegetables can also alter thyroid function (Schultze, 1998).