We recently adopted a 7-yr-old Chesapeake Bay Retriever/Great Pyrenees mix with a dark coat, and after about 2 weeks, my wife and I swear the fur is getting lighter, especially around his ears and neck. He eats well and seems pretty laid back, and although he sheds a lot and we've been brushing him regularly, he isn't developing any bald spots (e.g., from anxiety issues or malnourishment).
Is it normal for a dog's coat to change color, for example, with the seasons? Or is it possible for the coat to get sun bleached from only a few hours outdoors each week? It also occurred to us that maybe he was just a bit dirty before, but we gave him a bath when we first brought him home and his coat only started to seem lighter as of a few days ago.
Update: we have now had him for more than a year, and his coat has stayed about the same since that first color change a few weeks after we got him. We've fed him everything from the cheap $20 for 50 lbs food, to the fancy $70 for 24 lbs food (but we buy it when it is on a clearance super-sale), and his coat stays the same. I think in those first 2 weeks we had him, we were feeding him the same food that the shelter had been feeding him. So, strangely, his drastic coat color change doesn't seem to have been related to the seasons, and it seems unlikely it was related to diet or age since it was so fast.