The furred ones

It came without warning. Without preparation. Without even a hint of Armageddon. Yet, it hit. And it spread. Barely anyone is left. Find the survivors. Stop the spread. STAGES OF INFECTION: Stage 1: slightly more body hair, sharper teeth Stage 2: elongating face, signs of aggression Stage 3: stretch marks on face, foaming of the mouth, reached capability of infecting Stage 4: skin and muscle torn off of newly canine-like skull, highly aggressive Stage 5: size tripled, extremely fast, thermal vision, most aggressive