the situation is unclear but it's probably about the double death at the fox-hunt

In case of literal meaning, Peachey was right. However, in case of beyond our thought, you could see that in different ways. Men, horse and fox are similar in several ways. They all smart, wild, cunning sometimes if they wanted to have what they could not. In gambling, men and horse have higher value than fox's tail especially if they come from the best breed.

In context, both the horse and rider died when they misjudged a jump. They were actually taking part in fox-hunting at the time.