While they may need few calories in a day compared to large dog breeds, toy dog breeds need more calories per pound of body weight than larger breeds. (animalso.com)
This being the case, he may need more calories per pound of bodyweight than larger breeds — somewhere between 30 and 40 calories per pound. (pawster.com)
Small dogs require more calories per pound than their large breed counterparts, but why? (littledogtips.com)