When we had horses with an electric fence I would touch it to test if it was working - slight shock but not too painful. One day I accidentally touched it when my bare feet were in mud, never again, worst shock I've ever had in my life and I've had a few. If I remember correctly, in the UK voltages over 50V are not allowed in stables as they can be fatal to livestock. Different conditions (especially wet ones) can result in very different outcomes.
Mike.
Mike.