my mare started doing the same this year. She has rubbed her mane out at the base. I bought some tea tree and mint shampoo and washed just her mane and tail as and when i felt there was a build up of oil in the mane. Sometimes once a week, sometimes less. Seems to have worked well. She has not pulled any more out since and her mane and tail are shiney and soft with less oily build up. It also keeps the flys away!!

Thanks for all you comments, but she hasnt really rubbed it this year, fingers crossed, and its begining to lay over to one side now. Thanks for the help!

hi .... last year dane rubbed his tail so badly that it was full of scabs and very sore .... so i started to feed him garlic along with brewers yeast tablets and i spray his tail and mane every day with avon skin so soft dry oil ( the blue one, known to keep midges away). he has been turned out since the begining of may and so far he has had no problems at all. now he is turned out he has 1 clove of galic a day and 3 brewers yeast 300mg tablets anlong with his daily spray. hope this might help