A friend of mine indicated that most growth in the first year for 'most breeds'is skeletal growth and in the second year they kind of beef up with muscles, etc. It's worked that way in my home at least. Cassy and Livvy don't seem to have grown much since their second birthdays... Cassy is basic tabby and Livvy is a Maine Coon mix. What breed is Max: Siamese??? I'm not sure what their growth pattern is...