Why don’t the teeth of animals decay though they never brush their teeth?

According to WHO, decaying of teeth is a localized, post-eruptive pathologic external process, involving hard tooth tissue and formation of cavities. There is demineralization of teeth by acids produced in the oral environment, due to action of oral acidogenic bacteria on carbohydrates found in cooked food and drinks. Animals are either herbivorous or carnivorous or both, and survive on uncooked, raw food, rich in fibre, which needs a lot of chewing to digest, thereby cleansing the teeth naturally. It is like brushing teeth and massaging gums the natural way. But tooth decay is common in pets like dogs, which eat cooked food and junk food like biscuits etc.