Or take it to on leash only places where you have distance from other animalsYou train it, and take it for walks in places where you are unlikely to see other dog owners. Like around the street.
If Fido is too retarded to be trained to actually behave around other animals then sending it to the great hunting ground above is the best option.
And if a dog is let off leash in an on leash only area and gets mauled, that's not my dog's fault.