Does any body know why my golden bite herself and tear off her hair (near her back and tail). Please help
That's weird, it seems like your post just showed up. Or maybe I missed it. Anyway, fleas can cause exactly what you describe. So can other things. If you don't know what it is, and it is bad, you should have the vet look. Sometimes if the dog keeps biting and scratching at fleas she can get a skin infection, so you have two things to treat. jdoee
Just appeared for me too. In addition to fleas; teeny, tiny (unable to see with your eye) mites/mange can also cause chewing and baldness. Take her to the vet to rule out any health based reasons like anal sacs.

Dogs also chew on themselves when not getting enough exercise, if left alone for long periods or from allergies.

Kristen and
Kali CD, CGC, TDIA, TT
www.kristenandkali.com
Does any body know why my golden bite herself and tear off her hair (near her back and tail). Please help.

It sounds like a medical problem. Something is making her itch. It could be fleas or another bug or an allergy or an infection. A trip to the veterinarian is in order.
Lia