
As a professional photographer let me tell you how it is

Video: from outside the ring you can video your own dog but you should ask permission before videoing anyone elses dog. (KC). An exhibitor is perfectly entitled to ask for videoing of their dog to cease and I have myself done this on one occassion (the whole class insisted it was stopped, not just me, as the videoer was of dubious repute)
Stills: From outside the ring you can photo graph anydog EXCEPT at certain shows where they cleary stipulate in their own rules that there is to be no photography without owners consent.
under our KC regs you cannot come into the ring until all judging is finished & even then you must ask the judge if they are still in the ring. problems occur at shows like Crufts where either lay people who dont know the rules, or, more commonly, foregn exhibitors crowd into the ring during judging....this is allowed in may other countries so they dont realise its different here. Whilst working in Europe in the summer I was amazed at people going into the ring as the judge was going over a dog, & photographing it without anyone being atall bothered!!
i think thats what you asked for? Regarding publishing images, well thats a whole different ballgame & I have a whole book dedicated to the subject, so certainly wont be able to answer it here tonight!