It is a common misconception that chewing of a crunchy food will clean a cat's teeth. Your cat's teeth are pointed, so they split the food like a pick on ice. Only the point is cleaned and the food never scrapes along the sides of the pointed teeth. Instead, the food fractures into small pieces and lodges between the teeth and gums. The lodged food particles foster bacteria and produce plaque and tarter which lead to gum disease. Starch and sugars are often the main growing media for plaque and most dental foods contain up to 30% starch.
Our food is small and designed to be swallowed whole, no chewing necessary. Virtually nothing sticks to the teeth and there is even less starch for the plaque to form on.
Assuming that your cats are older, we would recommend our ZERO Mature Cat Food. This food has less than 1% starch and is easy for most cats to swallow whole.