Generally Speaking . . .
Canned foods generally are best to provide a high-protein, low carbohydrate dietary combination. Most dry foods are energy dense and have greater carbohydrate concentrations (greater than 25% on a dry matter basis) because starch is necesary to make the kibble.²
Canine Nutrition
Feline Nutrition
Cats eating commercial dry foods will consume approximately half the amount of water (in their diet and through drinking), compared with cats eating canned foods.¹
Resources
¹ Small Animal Clinical Nutrition, Fourth Edition 2000; Normal Cats pp 291-351
² The Carnivore Connection to Nutrition in Cats, Debra L. Zoran, DVM, PhD, DACVIM, JAVMA, Vol 221, No. 11, Dec 1, 2002.
