What do you have to do, to become a dog show judge.

I'm not 100% sure of the exact details, but here's a start. I'm sure some people on here who are judges will be able to fill you in much better than me.

Show your own dogs for at least 5 years for starters and preferably breed some dogs that do well at shows if you want to be taken seriously. Do some stewarding, get involved with your breed club and get yourself on the approved judges list by fulfilling the criteria of the breed club judging lists of a few of the different breeds you're interested. Then you can work your way up the lists by attending their organized breed/judging seminars and getting good enough marks on the exams and more years experience to eventually work your way up the different lists. Wait for somebody to give you an judging appointment, bearing in mind the more judging experience you have, the bigger and better shows you will be asked to judge. You'll probably start by getting offered a small open show or similar and these will hopefully lead to better appointments. It's quite involved and can take years - the people you see judging at Crufts have often taken 30 or 40 years showing and judging to get the honour of being asked.