It's hard to believe Dagon is already a year old. It seems like only yesterday he was chewing up my socks. Well, he was chewing up my socks yesterday, but he used to be smaller. A lot smaller.
Throwing birthday parties for dogs seems kinda silly. At least human children conceivably gain something from being among other screaming children. Puppies on the other hand would likely just fight to the death over the birthday bones.
Private functions are best, I believe.