About the Excretory System of Wolves

The wolf has had a bad reputation throughout history as a thief and murderer of livestock and as an enemy to society. Through a short comparison of the dog gut to the wolf gut, we see the extreme similarity of the dog to the wolf, and thus gain a new appreciation for the wolf as the genetic ancestor to the modern dog.

Considerations

Pliny, the famed writer of the first century, spoke about the ravenous and greedy wolf that abandoned its dinner when it discontinued looking at its meal. Even the entrails of the wolf are thought to have evil powers. A writer named Bartholomaeus Anglicus wrote that a stringed instrument with a single string comprised of the innards of a wolf will ruin the strings of the entire music making apparatus.

History

Over a dozen-thousand years ago, the wild dog became domesticated into what we know as the various domestic breeds today. Lap dogs still share the same genetic material as they did with wolves a millennium ago.

Function

Scientists report that the dog and wolf digestion system are the same from the mouth to the stomach, intestine, and excretion apparatus. Dogs and wolves have eyes in the front of their heads, in order to hunt and see prey at a distance. Both the dog and wolf have jaws that move up and down that are not designed to eat vegetable matter but are built to chew flesh, with a powerful leverage and sharp teeth. Herbivores contain an enzyme in their mouth in order to help digest the carbohydrate of plant cell walls, but dogs and wolves contain an enzyme that kills bacteria. Additionally, the wolf and dog stomach expand to fill with a meat meal from the hunt, and the pH is very low in order to kill bacteria. The remainder of the gut is designed to remove the undigested matter, as the intestines are small.

Effects

It was shown that when dogs were put on a lower carbohydrate diet, they were able to lengthen the life of the dog by over one year. It was shown that increased carbs in a dog's diet indirectly reduced the body's ability to break down lipids. Thus, although humans eat carbs in the form of vegetables and fruits, dogs do not need to have large quantities of carbs to be healthy. Fecal colonies from beagle and human gut have shown to be highly different in content. Additionally, the regular domestic dog has very strong bacterial colonies in the gut that are able to resist a variety of antibiotics. This means that the canine gut bacterial colonies are able to withstand onslaughts of infection and disruption by whatever the dog eats.

Misconceptions

Some argue that wolves eat vegetable matter because their prey eats vegetables, and so the wolf eats vegetables when it eats the prey, such as deer or other herbivorous animals. Scientists debunk this theory, as the stomach of an animal is tiny in comparison to its entire carcass. Additionally, vets note that the smaller stools of all-meat fed dogs point to the better efficiency and decomposability of the mostly-meat dog and wolf diet in its gut. Some say that the dog is too far removed from the wolf to eat raw meat, but dog enthusiasts say that because we are used to feeding our dogs pre-packaged kibble. However, the mitochondrial DNA of regular dogs is so similar to that of wolves that dog owners argue it is ridiculous to argue that the dog can't eat raw meat. Mitochondrial DNA process the air we breathe and combine it with basic sugar from our food to make the energy we use. Mitochondrial DNA also help make proteins from basic amino acids. If dogs and wolves have similar digestive systems, it would make sense that their mitochondrial DNA is similar. Scientists have shown that dogs and wolves have more similar mitochondrial DNA, than wolves do to other wild dogs, such as prairie wolves or other pack hunting wild dogs. Others argue that wolves have the wrong diet, because they don't live as long in the wild as domestic dogs that are given plant matter as well. These arguments, however, do not take into account the stressful life of the wolf--the lack of food for days at a time, living in the cold and the rain and being subject to the stereotype as the sly hunter out to kill livestock and domestic animals.

Resources

• Scientific article on dog gut bacteria