Dog food depends on the size of the dog. It also depends on the breed. Every breed has its unique needs when it comes to food. The same is true with its stature. The food required by a big dog is entirely different from that of a small-sized dog.
The categorization of dogs into small, medium, and large is quite a debatable but interesting topic. Normally, a dog is considered small if its height is less than 12 inches. Similarly, a dog weighing less than 22 pounds can be categorized as small.
On the other hand, dogs are also categorized per their breeds. But it is very possible that a dog may not belong to a small breed though it comes under the category of small dogs based on weight or height.
So, the best criterion is a dog’s weight, which defines whether it is a small dog or a big one. Any dog that weighs less than 22 pounds while fully grown would be considered a small dog regarding its food needs.