In some regions its extremely popular and herding dogs still seen, not as popular as once though. My state has the worlds largest population of wild pigs, they outnumber people 2-1. The two types of dog or method are bailers and luggers. Bailer is anything that finds and bails the pig up(rounds it up), aka keeps it in position so you can shoot it. Luggers are dogs big and strong enough to hang on aka lug on to the pig so you can shoot/knife it. Both dog types can technically do either, a lot are crosses these days.Knifing pigs once lugged is very common in tropical rainfoirest as you often need dogs to find the pigs and there is little room to manouvere anyway. In the day lighter 'working dog' breeds ( heelers, herders etc) were more common as most people didnt have access to the heavier breeds , or the affordability to feed 3-4 of them, also the potential vet bills as big lugging dogs take the pig on directly. Smarter money back in the day was on smart bailing dogs that took less risks, didnt cost an arm and a leg to feed and got stiched up less. A lot of dogs these days are wearing sheilds, aka leather or synthetic neck and shoulder protectors. Various businesses and custom makers do a a roaring trade selling them. If you want some more info get a subscription to bacon busters magazine here.