Obviously no pain, no sign of damage or distress. Giles frowns, thinking hard on how best to approach the situation further. Perhaps a stone in a shoe...?

Then he realizes that the horse just stamped her injured leg in response to his musings that said leg might be injured. Horses are bright animals, of course, but...

...hm...

Well, it's worth a shot. Giles looks back at the horse and asks, as politely as he can, "I don't suppose you'd let me check your shoes, would you?"