I use Oak Beck vets opposite Pets At Home (also called Pet A&E) - they are a 24 hour vets so always someone there with the animals and they use the best anaesthetic for buns and have £25k's worth of anaesthetic monitoring equipment for when a bun is under GA.
They also have another ranch up Leeds Road, (and one in Ripon), so you can always get in somewhere if its urgent.
Bob and Ann are the vets I prefer for the buns, but all the vets there are good