Let's say a boarder's horse was brought in from the pasture for feeding time and she was found to be injured. The injury is a pretty severe gash on her hock that is bleeding profusely. The horse becomes shocky and almost passes out a few times while waiting for the vet to come out. When the vet comes out she is sedated and sutured up, however it is found that she has severed several tendons and will require a lot of stall rest for possibly months and definitely no riding.
The next day the cause of the injury is found. It turns out that there was a pile of tin behind the water trough. Somehow the horse must've have been near the water, zapped herself, and slid her leg under the fence and cut herself. This has to be the cause because blood was found on the tin.
Here is my question. Since this is a boarding horse, is the BO in any way responsible for the vet bill and loss of $$ to the owner since the horse is unrideable?