Sally Van Nostrand plays with a friend's dog at a birthday party for her dog, Star, at Bow Wow Blues in the North Valley. Birthday parties for dogs are a growing trend, those in the pet pampering business say. "My grandchildren live on the other side of the country and these are my surrogate grandchildren," Van Nostrand said of her two dogs. "When you don't have children around, you get just as attached to your dogs as you do your children."