I'd not say impossible in E&W. If the dog is happy & experienced enough it will catch or kill or bay well enough for you to finish it with a knife, personally I've been amazed how little attention a bayed deer /hog pays to the man sneaking up on it with a knife and that the dog seems to know what to do, switching from baying, holding & turning the beast. That's kind of my point, if you've not got an experienced dog chance of failure increases massively.
I have often wondered / considered that perhaps some of the larger specialist breeds and crosses are better suited to ending suffering in E&W, or working them in pairs / packs like I have abroad (legal issues with packs duly noted) That said I've seen Teckles bay boar very effectively.
In my experience, once the dogs in Alabama got the scent of a hog, success was 100% but that was not hunting a wounded individual and crafty boar would run towards groups of sows & youngsters to save their own bacon, many of the dogs were dogo / apbt crosses too. A pack would often be made of several different specialists with tracking / baying hounds and then the bigger boys to strike / catch