Interesting question Nic.

Never been a cat owner, but for our doggies and birdies we stick to as natural as possible... 'would they eat this in the wild?'

Teni, I would think genetics would determine the size of your doggie as opposed to it's diet. My girl is small for her breed and gets the all clear at her annual check up. We gave her the best diet for her first 12 months, followed the diet plan from the breeders and vets without fail. After the 12 months we stopped buying the premium plus dry food as it was costing a absolute fortune.