Erik,
 
In re-reading your post, you mentioned using Iams CAT Food - I HOPE you
are really using Iams KITTEN food - if not, switch immediately to a kitten
formula - it has a higher protein and higher fat content - all essential
to a happy and healthy ferret.  I do not recommend using an adult formula
of anything until around 3 years of age.
 
Debbie Riccio
WNYFLFA
Rochester, NY
[Posted in FML issue 1184]