Siku, a polar bear at Lincoln Park Zoo, developed allergies to various substances including human hair dander (Credit: ...

A polar bear accidentally killed another polar bear as zoo visitors watched on in a tragic case of rough play. A necropsy has ...

But what would a polar bear be allergic to ... like the itchy female rhinoceros and her calf from New York's Bronx Zoo that developed severe rashes, bloody ulcerations and weeping infections.