The local Three Dog Bakery near me, offers a b-day party service.
http://www.threedog.com/
The price was pretty inexpensive (some price under $100 definitely). You get to host the party there an hour before opening. All dogs get full run of the store. You are encouraged to invite all of your friends (and their dogs). And, your dog gets his own b-day cake! Three Dog Bakery sells lots of treats too, ranging from simple cookies to tarts to cakes.