Children in Edmond are being diagnosed with Hand, Foot and Mouth disease, and at least four parents believe their children got sick after playing at a local splash pad.
But city leaders said there's no way to tell because the illness is contagious.
Doctors said if a child gets sick with the virus, it's important to keep them away from others until the open sores on their hands, feet and mouth have healed.
"You do have to have a clean bill of health and all of the sores have to be scabbed over before they'll let you bring your child back to any facility," said Jessica Austin, who is a mother.
The blisters typically last one week.