Problem
Your favorite hamster Rex has been exhibiting symptoms of a micronutrient deficiency. Among other things he doesn't run on his wheel as often as he used too, is walking very stiffly, and his hair coat is not bright and shiny like it used to be. What micronutrient deficiency is Rex suffering from and how does this explain his symptoms? Once you've diagnosed the deficiency, are there any secondary deficiencies to worry about (include why)?