The mysteries of canine digestion revealed

The bond between humans and dogs is so close that it is easy to forget that, being different species, we have markedly different digestive systems. Dogs actually have the same digestive system as the grey wolf and, therefore, need to eat the same diet.

The word ‘need’ is worth stressing. Every living creature on earth must eat a biologically appropriate diet. Some species have a greater tolerance than others, but no species thrives on an incorrect diet and many become ill and die. It is possible for a species to partially adapt to a new diet. Palaeontologists believe that this change takes at least 100,000 years.

Meat glorious meat

Dogs are carnivores. True, they can and do eat vegetable matter, but anatomically they are designed to catch, kill and eat prey. As with other predatory mammals, they have powerful muscles relative to their size, fused wrist bones and a cardiovascular system that supports both sprinting and endurance. And a quick look inside their mouth is all it takes to understand why they are really much, much closer to being carnivores than omnivores.

Your dog’s mouth is a bit like a Swiss Army knife

No matter how sweet and innocent a dog may look, the inside of his or her mouth tells a different story. Dogs have five types of teeth, each designed to perform different and precise functions: fang teeth to catch and kill prey and to tear off meat; front teeth to scrape meat off bones; small incisors to grab and hold; large incisors that work like scissors to cut sinews and muscles; and molars to crush bones.

None of these teeth, however, is capable of grinding food. Indeed, if you gently try to move a dog’s jaw from side to side (necessary for grinding and chewing) you’ll find that it is impossible. A dog’s jaw can only move up and down.

All the action takes place in the stomach

A dog’s digestive process starts in its stomach. This differs dramatically from humans. We use our teeth to grind our food and moisten it with saliva containing digestive enzymes so that the digestive process is well in hand by the time we swallow.

Dogs, on the other hand, don’t have any digestive enzymes in their saliva and even if they did it would be useless because they can’t grind their food, owing to having jaws that only open and close. Instead, they gulp their food with a view to getting it to where the action takes place (the stomach) as quickly as possible.

What happens when the food arrives?

The stomach starts to produce digestive enzymes and other chemicals to break it down into small molecules that can be absorbed and used by the body. Some of these enzymes are produced by the pancreas, but many are produced by other small glands in the stomach wall itself.

To help the digestive process dogs have extremely strong and corrosive stomach acids. Acidity is measured using something called pH. Neutral is pH 7, but when a dog is digesting food its stomach operates between pH 1 and pH 2. Put in plain English: if you touched the natural acids in a dog’s stomach, you would burn your fingers.

Another important point in relation to this is that most enzymes are extremely sensitive to pH and won’t function in the wrong environment. If a dog eats inappropriate food then its digestive system can’t function properly.

Dogs have evolved to eat a lot, quite quickly

Dogs can consume up to 5% of their body weight in an extremely short period. To put this into perspective, it would be like a 10-stone human eating, say, seven pounds of food in a single sitting. A dog’s stomach looks rather like an accordion with lots of folds.

It expands when full and its muscles massage the food to ensure that the digestive juices work properly. Once all the digestible pieces of food have been dissolved, the muscles squeeze the now liquid mass into the intestine for the final stage of the process and for the absorption of the nutrients.

A dog’s stomach is designed to finish digesting one meal before being filled again. This process generally takes longer than for humans, although it very much depends on what the dog has eaten.

Why dogs should eat a natural diet

Every species should eat what it is biologically designed to eat, in other words what it would eat in the wild or as close to what it would eat as is feasible.

Dogs are, essentially, wolves and, as such, are designed to catch, kill and eat prey. They have a markedly different digestive system from humans and shouldn’t eat the same diet as us, any more than we should eat the same diet as a cow.

For more information and advice please contact Honey’s – we’re happy to help even if you never, ever plan to become a customer.



Phone: 01672 620 260