Allergies, yech!
I had an extended test done on one of my Tervs long ago and he came back positive for 96% of the things tested and borderline on all but a couple others. That's plants and trees (allergic to all but borderline mullberry), foods (most), fibers (allergic to all but sisal), animals (allergic to birds, cats, dogs, horses, etc.). So long carpet, open windows, fuzzy chew toys, etc.

He did good with Nutro's lamb and rice, and a stainless steel bowl, thank goodness.