I was right!

Farrier came today, Bonny couldn't stand still to have either back hoofs trimmed. Mick was very good with her, trying not to hold her hoofs high while he worked. Her back right hock is the bad one, she doesn't flex the joint. So glad I went with my instincts and didn't ride yesterday. The vet is coming tomorrow to do teeth and vaccs, I'm going to get her to check Bonny, lets see if she can suggest anything.