What is the best food for my sick cat? Written by Russel in A What is the best food for my sick cat? Soft foods are the best for a sick cat. Feed your cat canned foods (wet foods) as opposed to kibble (dry food). You could also feed your cat chicken broth which is still healthy for a sick cat. Russel A pet owner who loves to share useful facts and information about animals. For now, I write mostly about dogs and cats.