Safely Handling ADD meds

My husband takes both Concerta and Wellbutrin. He has a bad habit of not putting the caps on tight when he takes them. We have cats that climb on the counter (I know that's not good but I can't figure out how to stop it) and I'm afraid the cats will knock them on the floor and either the cats or the dog will eat them. Does anyone know if that would harm an animal? Does anyone know how to get him to remember to put the caps on? I don't want to give them to him like he's a child because he's 47 years old, but if something happened to the dog or cats he'd never forgive himself and I'd never forgive him either.