Hi, I use one called Robin Harding for both of mine who is very good. He is based in Cheshire I think, but does travel up to me in Chorley. I found him via the EDT website
Diane Holliday covers Lancashire. We use her and she's excellent... very patient with the horses and always explains everything she does to the owner. She's on the EDT website if you look under North West... http://www.equinedentistry.org.uk/