I don’t know who came up with the idea of hunting with a leashed dog, but I’ve run into several hunters who have done just that. The black Lab I rescued this year was wearing an expensive camo leash which tells me that’s what her owner must have been doing, and perhaps being gun shy, she bolted when the shooting began.
Dangers of a leashed pup.
Simply walking through brush, on uneven terrain with a loaded gun poses a risk, and people are accidentally shot every year. Add an excited pup who is straining at the leash and it’s downright dangerous for you, the dog, and anyone else in shotgun range.
Can you shoot?
Say you get far enough into your hunt to actually flush a bird, how does one shoot while holding a leashed dog? The only option is to drop the leash and then chase down pup who, suddenly free, has either given chase to the bird or run the other way. Any pup that needs to be on a leash is certainly not going to be steady-to-wing-and-shot.
What does it do to future training?
Whether their range is being limited by a leash or e-collar, pup is being trained to hunt underfoot. Unless that’s all the hunter wants out of their dog, they’ll have to later correct problems with range and quartering. Someone who starts their dog out this way likely doesn’t know enough about training to be able to correct those problems.
No shortcuts to training.
There are no shortcuts to training, if that’s the intent of hunting with a leashed dog. The only real shortcut is to get it right the first time and that means understanding your own strengths and weaknesses, understanding your dog, and understanding the training methodology you choose.