Ellie was very under weight (on a scale of 1-10, perfect is a 5 and she was a 2 or 3

). I think what helped her gain some was steel cut oats. They are full of calories. Most of the time, skinnier dogs are at a good weight but the owner thinks they are too skinny, so I'd go with what your vet says. Ellie's vet said when she is hungry, let her eat. She is probably at a 3 or 4 now.