Modern day society has a way of forgetting who dogs are and where they came from. Let’s take a step back and look at what a dog really is, their anatomy, and their relatives.
The Domestic Dog
Canis lupus, the grey wolf, is the closest living relative to the domestic dog, Canis lupus familiaris or Canis familiaris. In fact Canis familiaris is just a subspecies of Canis lupus. The domestic dog and the grey wolf can interbreed and produce hybrids with no effects to communication or fertility. On the other hand, studies have proven hybrids between coyotes and dogs have a documented decrease in fertility as well as an increase in genetic disorders further proving the domestic dog is closely related to the grey wolf.
It is very easy to determine the similarities when looking at a domestic dog in comparison to the grey wolf. However some domestic dog breeds have gone through selective breeding (Boxer, English Bulldog, Pug) which has changed their overall appearance; but their physiology and ancestry remained the same.
Skull, Jaw, & Teeth
Looking at an animal’s teeth is a good way of determining the natural diet of that animal. Not only is a dog’s overall appearance similar to a grey wolf but so is their skull, jaw, and teeth which is designed to shred meat and crush raw bones.
Dog’s do not have salivary enzymes like humans do. Human’s have amylase in their saliva which helps break down starch into sugar before it leaves the mouth. However a dog does not have these enzymes so the starches tend to stick to their teeth causing plaque and tartar to build up.
“Dogs (and cats) are equipped with powerful jaw muscles and neck muscles that assist in pulling down prey and chewing meat, bone, and hide. Their jaws hinge open widely, allowing them to gulp large chunks of meat and bone. Their skulls are heavy, and are shaped to prevent lateral movement of the lower jaw when captured prey struggles (the mandibular fossa is deep and C-shaped); this shape permits only an up-and-down crushing motion, whereas herbivores and omnivores have flatter mandibular fossa that allows for the lateral motion necessary to grind plant matter”.
Feldhamer, G.A. 1999. Mammology: Adaptation, Diversity, and Ecology. McGraw-Hill. pgs 258-259.
The digestive system of a dog is built like a carnivore’s, it is short and very efficient at processing raw foods due to the high levels of hydrochloric acid and carries a ph of about l. The acidity in a dog’s gut plays an important role in killing ingested bacteria and processing raw foods. An adult dog only needs 4-6 hours to complete the whole digestive process for raw.
Once food reaches the dog’s stomach the digestion process begins immediately. Stomach contents are turned into a liquid then passed to the small and large intestines for nutrients to be absorbed. Since a dog’s digestive tracts are relatively short and simple, they are unable to fully process large amounts of grains and fiber. These foods simply pass through, leading to more waste to clean up.