Like Gray said, how do you KNOW it doesn't have parasites? Are you doing fecals? Not just a single fecal test but multiple ones weeks apart.
I am going to go ahead and make a blanket statement that all wild animals carry one parasite or another, the parasite usually never causes a problem until the immune system drops and then the parasites may be noticed.

You have said you already did it before so why ask now? It's up to you, but I value my animals more than to take that unnecessary risk.