Tonight my kirby has been all lovey dove all over me then when I went away for a hour I come back down to stop him from barking outside he comes in just grumbling and growling. Kirby then proceeds to lay on him back and want me to pet him but he growled everytime I did so no matter where I touched him. I then proceeded to nudge him ever so slighty trying to get him to stop he suddenly turns around and bites my ankle and he left a hole in my ankle bleeding... this is the first time I've ever posted on here because I am so alarmed by this this agression was just so sudden he's been really good the last few days I thought he was finally mellowing out after a year of being with us.. So any help? Does anyone think it may be a medical condition?