I caught a glimpse of my 10 year old best pal, Marbles the other day and realized just how frosted his little nose had become. Why do dogs go grey? According to Puppyleaks.com (Awesome site name) it can be two reasons. One is genetics (which is also why my hair is going grey at 35 so I must continue to dye it until it falls out) or it can be anxiety and stress. Dogs with high levels of freak outs like Marbles can grey early just like stressed out humans can. On average it starts around 5 years old but can start as early as 2 in some mutts. A little white around the muzzle on Marbles doesn’t look so bad though…who knows… maybe it’ll get him more respect at the dog park.