I always carry my my dog's complete medical records with me. I keep them in a file and just grab that file folder when I pack up. It was valuable when my last Golden became suddenly and seriously ill while traveling. Unfortunately she did not survive, but the vets had plenty of background information that helped in their diagnosis.
To unlce t the original poster:
You lost all credibility and any concern from me when you implied that you would lie next time when asked about any pets with you. You are the reason why park owners ultimately just ban pets from their parks. Some pet owners, you included, don't think the rules apply to them.