Jim,
don't forget toys and other baiting materials! Are you going to process credit/debit cards? If so, bring the forms and the machine to run them.

Otherwise, sounds like you have all the bases covered. Make sure your batteries are charged and bring a spare just in case but with 3 bodies I don't think that'll be an issue. I hope you take enough pics to exhaust a battery or two!

Good luck. Work hard but don't forget to have some fun and to make it fun for the people and the dogs. That's the one thing I try to bring to the equation when I shoot a show and it's the basic reason I get invited back. Folks enjoy their time with me. And so do the dogs. So, don't be uptight. Be confident you have it all covered and just concentrate on giving good portraits.

Jim