In my opinion 4/5 by then they have had 2/3 good seasons work, ran hard and gained experience, I try to work them often and as much as I can in their first two seasons, this is the time they need to see plenty, gain fieldcraft and learn the score prey and running wise. Once a dog reaches 7, if it has been worked hard all its life generally it takes its toll, either pace, injury, stamina starts to decline, yes still good workers and a lot to offer but past their peak, my old lad is 13 in January and is out every morning, if they put something up, hes second to it and usually tires after 2/3, n