How can you stop a horse from rubbing its tail and making parts of it bald?

Hair eating is often linked to a mineral deficiency, but it can stem from boredom. Pat Coleby recommends seaweed meal, also known as kelp meal, in her book Natural Horse Care.

Feeding kelp meal can limit or eliminate some unwanted behaviors including mane and tail chewing, wood chewing and even cribbing because of its naturally high and balanced levels of minerals. I have used it for years and seen huge improvements in my horses.