First Right of Refusal in Horse Sale Contracts

Q: I unknowingly purchased a gelding from someone who had agreed to a “first right of refusal” with the person from whom she’d purchased him. However, I’ve now been told that the seller (who I bought the horse from) did not honor the first right of refusal with the previous owner (who she purchased the horse from). I’m concerned that someone else’s agreement, which I wasn’t aware of, could threaten my ownership of the horse. I paid for the horse and have a bill of sale. Do I own the horse, and does the previous owner have a right to h