Why Does My Cat Bite His Tail Until It Bleeds. You may notice that she twitches, vocalizes or has muscle spasms just before she bites at her tail. Although tail chewing can be caused by allergies, this behavior can be a symptom of a few other conditions.
This condition causes a cat's skin to become very sensitive. A medical condition known as feline hyperesthesia syndrome could cause your cat to bite her tail. Even if you don't see any, there's probably some there and some animals are allergic to fleas so it only takes one bite to drive them absolutely crazy.