Mine don't get 'normal' walks as such when they're being trained to work. As pups they get several short training/play sessions every day plus a couple of play/mooching sessions with the other dogs but only in a suitable area where I can keep conditions controlled in terms of scents, wildlife, cover etc. They're not on lead but I'm watching them the whole time and making sure I can get their focus back at any time. If I did want to do a long walk and/or it was an area I couldn't control and watch them at all times they'd be on a harness and flexi lead or long line though.
Caoimhe was different as she was trained for trialling so her training/exercise was extremely carefully controlled right up until she retired last season after becoming FTCh at almost 4 years old. With Rodaidh I was able to relax earlier, he started his first full working season at 21 months old and after that once I'd established his trustworthiness and steadiness I could relax on his training/exercise a lot more. With a pup though you have to be consistent if you want consistent results, otherwise you're just confusing them and potentially creating issues. It's hard work and very intensive when they're young but it certainly pays off for me.
