[OwnedByJezebel]

What brand were you feeding her when she got sick?

It sounds to me as if she could have an allergy to one of the ingredients in the Iams. What is the protein source in the Iams, and what kind of grains? (Rice, corn, etc). It could also be an environmental allergy, not food related at all, so you're not going to know how to help her until you can determine exactly what it is that she is allergic to.

I would see if you can get her into see a specialist and run some tests to find out what she is allergic to. If it is environmental, then she'll probably be on meds (steroids, Zyrtek, etc), but if it is food related then you can address it by reading the food labels and avoiding the culprit.