The Best Why Do Cows Eat Tree Bark 2022. Some horses, in fact, do more than nibble. Dogs left alone for long periods, whether in the house or in the yard, can become bored or sad and often will bark because they are unhappy.
A neighbor has two cows (well, actually a cow and a bull) that are eating bark off of several trees. Horses will chew on things when they are mentally bored. Seeking or trying to consume something that is not considered “normal” food for the animal in question is called pica.