My pet yorkie is 14 months old and he has always fed very well. But for the past few months every time I give him his food he keeps looking behind himself at his tail. He growls and goes for it. This only happens when food is around. He has also stopped eating his food. If I pick up the food with my hands he will eat out of it. I am worried now as he has gone from eating 3 meals a day to hardly 1.