Thank you both. She refused a disc shaped crunchie tonight
But is eating grass, hay (although less than usual) and had plenty of herbs/veg. I am fairly sure it's her teeth as there's no other symptoms and she will go to bite a crunchie but then pull away, if she can't have the dental tomorrow she will come home with pain killer until it can be done hopefully tuesday.
On another note, I have just discovered scent glands
Beano sometimes has issues with a slightly runny bum if she has too much veg so I check her regularly and checked her this evening and saw a black, crusty line next to her vulva so gave it a gently 'poke' and it looked like an opening. I panicked, thinking it could be a tear in her skin or something until I noticed the same at the other side and after a quick search I've gathered they're scent glands. Does anyone know if they need cleaning if black, crusty stuff is visible or is this normal? A couple of small, black chunks was on her fur so I eased them out but obviously don't want to poke down around there when not needed. I will ask the vets tomorrow anyway.