Thanks for the reply so quickly
I have always feed Mickey Royal Cannin puppy food 33. About a month ago I ran out and the petstores were closed so I picked up Iams small /toy breed food. Mickey seemed to really like his new food so I bought another bag(15lbs). He was about a 1/4 of the way through the bag and noticed he had been losing a lot of weight . I could feel his hip bones and spine. So I went straight back and bought more royal cannin and some solid gold wet food(hoping to put some weight back on him). It's been almost a month and Mickey has put some weight back on ....still needs a little more. I would just like to make sure I am not putting my babies in danger. He is only 2.9 lbs (that is what he weighed before the weight loss) so any weight loss is a big deal to him.