My little MewMew had the same problem and she had fleas that she was highly allergic to....I got the fleas cleared up and her hair grew back. She is also a longhair, but not a ragdoll....
I could not find any fleas on her or in the house, but the vet told me that I should go home and "Pretend Then" that MewMew had fleas, vacumn, get rid of blankets that she slept on and replace with clean bedding and start treating her with Flea Medication. Once I started to Pretend that we might have fleas, all has been well...
The best of luck to you
M
hi....this is a very common problem and most always due to food allergies or intolerances to the grains in the food(especially dry food)
I will give you a couple links to where I responded to the very same issue just lately, read thru these and if I can be of more help please post again.
http://www.medhelp.org/posts/Cats/MY-CAT-IS-PULLING-OUT-HER-HAIR/show/1886536?personal_page_id=861539
http://www.medhelp.org/posts/Cats/my-cat-is-licking-herself-bald/show/1884458?personal_page_id=861539