I've only had it once an old import saluki I got gifted had a good 4 min course killed her hare then on the way back to us another lifted she had a grueller about 5 min killing that one I got to the bitch she found a puddle and laid in it started pissing blood after. she came right in the end but I always carry a mars bar and kids fruit shoot bottle with electrolytes in for them just in case they go jelly legged