the trick is to keep an eye on them when lamping and look for signs of tiring a good dog man can notice adog tiring ,if they are back on leash and rested while leash walked , ive ran the large arable land for along times , useing jeep on foot ,always have fresh water and the odd occasion electo saw dogs taking the odd wobbly as they say ,but not much ,ive used gator ade , and home made electo , and rehydrate ,i always keep an eye on the dog when lamping and make sure there fit for a nite out only way