Not only does this make digestion perfect since a dog is a carnivore, it also creates a safety buffer because meat is a solid substance. The stomach outlet is closed, so gastric juices are lowered to 2pH, digestion is perfect and in the acid environment all damaging substances such as bacteria, worm eggs, etc. are killed. This is because they cannot survive at a pH level of 2 — luckily for wolves, dingoes, jackals and foxes because they cannot just pass by a vet for worming.
With natural food, the process is the same for a domesticated dog. However for various reasons, they must be vaccinated and wormed at regular intervals, even when being given natural food.
For every gram of dry food a dog eats, he must drink +/- 2.5 grams of water. Tap water usually contains a lot of calcium. Calcium neutralises acids, the result: a less functioning digestive system. Because the acidity level cannot be lowered to 2pH, the chance that worms, worm eggs or damaging bacteria can survive becomes higher.