Beware: moldy walnuts are toxic to dogs!

A colleague of mine recently noted that, “It’s moldy walnut season again.” So, I thought moldy walnut toxicity would be a great topic for a post: Why are these walnuts moldy and how does that affect you?

The walnuts of concern are those that fall from trees and remain on the ground during and after wet weather. As they sit there through the cool, wet winter season, a mold forms on them; and although they can turn a furry black color, they often appear completely normal. Once the mold has formed, they are very toxic to dogs, horses, and virtually any other mammal willing to chew on them. More