How we digest our food is very different from the way dogs complete the same task. Even the food itself is very different. Some of our food is processed to make it easier to digest.
We gather around the dinner table and between moments of witty repartee, demurely introduce a modest fork or spoonful of food into our mouths, chew it anywhere from 10 to 30 times, and let it slide down the hatch.
A pack of dogs, on the other hand, would gather around the carcass and between moments of fierce competition, rip off a huge chunk of something, chew it once or twice, and as its going down the hatch, be clamping their jaws on another chunk of something.
We’re designed to eat several small meals each day. Dogs are designed to eat one big meal because, in the old days, they never knew when they’d get their next meal. It could be a day or two, or even longer, before they’d eat again.
We have relatively small stomachs (for some of us, in our dreams) that accept food which has already been partially broken down; by chewing and mixing with our saliva, which contains powerful enzymes that begin to break the food down.
The dog has a relatively large stomach with an extremely acidic environment; loaded with powerful digestive enzymes and up to three times as much hydrochloric acid as we have. Those huge chunks of food are lubricated with saliva and slide down the hatch into a stomach that grinds and liquefies the food. The saliva itself contains no enzymes.
The liquefied food, called chyme, then passes into the small intestine where absorption of nutrients into the blood stream takes place, aided by digestive juices from the pancreas and gallbladder. Although the intestinal tract is about 4 times the length of the dog’s body, it’s still shorter than that of a human.
That’s because carnivores need the food to move quickly through their system because they’ve got work to do and can’t be lying around waiting for their food to digest. As nomads, they need to patrol and defend a territory, protect mates, offspring and other pack members, and they’re already hunting for their next meal.
In the large intestine, or colon, most of the water and minerals from the chyme are absorbed and the last hard-to-digest material is broken down by powerful digestive bacteria. As it exits the dog, the anal glands coat the waste with pheromones that are the animal’s signature scent.
Most domestic dogs gulp their food the same way their wild counterparts do, barely chewing it. Nor do they pause to savor the flavor; since they have practically no sense of taste. Satiated, the next time they think of food will be when they’re hungry, or when you open or cook something and the aromas get their attention.
We and our dogs look at food very differently. To us it’s an art form and a focal point of our culture. We take great pains to optimize how it looks, smells and tastes, and when company comes over, we bring out food.
To dogs, food is strictly utilitarian. They eat to live (while many of us live to eat).
Bob Bamberg has been in the pet supply industry for more than a quarter century, including owning his own feed and grain store in South-eastern Massachusetts, USA. He writes a weekly newspaper column on pet health, nutrition and behaviour and his articles appear at http://hubpages.com/@bobbamberg