hi jem, my two have harnesses, and i have put their tags onto them and don't have collars on them when i go out, they have got some but they are a tad too big and their old ones were too small. they are from my local pet shop but i think pets at home sell them. i prefer the harness as the collers wern't as secure and i can haul them out of streams better by the harness as no fear of it popping over their heads, and the collars were leaving a mark in their fur as they are really furry around the neck. don't know of any sledging places but you could get a scooter.