Tail Issues

I have an 11 year old paint gelding that ever summer the top of his tail falls out. He does not rub or itch his tail and I do regularly keep his sheath clean so I am pretty sure that is not the issue. Then ever winter the hair that he lost grows back. I was wondering if anyone has had this issue and what have you done about it.

What does the skin where the hair is lost look like?
What relation to his tail hair would sheath cleaning have??
Have you asked your vet about it?
How can you be certain he does not rub unless you are literally watching him 24/7?

The skin where the hair is lost looks normal and not red or irritated.
Gelding/stallions may itch their butts is theirs sheaths are dirty and they cannot itch them.
I have asked my vet and they gave me no answer.
No I cannot be completely certain that he does not itch his tail when I am not watching but sometimes you can when they are because the tail hairs are broken and you also can find them on the wall.

Thank you for your reply.

Well it kinda sounds like he is probably itching his tail.....I have two that do that and I spray their tale with cortizone spray.....every day for a week and then I slowly wean off to once or twice a week.........in order for the spray to be effective you have to get to the skin........so I part the tail hair in several spots and spray the actual skin.......I have had really good results.

I bought the spray for Entirely pets.....they come in 8oz bottles.

Super Nova

What is his deworming schedule like? Do you feed differently in the summer vs. winter (including suppliments)? How many years has this been a cycle for? Also, is he pastured with different buddies in summer vs. winter? Just a few things I am thinking about...

It makes perfect sense that it would be completely seasonal - especially if it is related to insects (gnats come to mind - no-see-ums that can irritate the flesh to no end) or heat/humidity which can also cause some irritation that would result in an urge to rub.
If it is irritation, it is likely irritation to the skin under his tail (his nether regions) which is one of those more delicately skinned areas prone to irritation. The tail is just a victim as it is between him and the area he is trying to soothe.

He is dewormed every 6 to 8 weeks in rotation with different wormers. I have have only had him 3 years and he has been doing every summer since I got him. The only supplement I have added was a feed through fly supplement but I did not start that until last year, so he was still losing his hair before that. He has also been by the same horses the whole time I have had him. I do not know it could be anything.

It could be flies and gnats or the heat and humdity because I do live in Florida. I do keep his sheath clean so that should not be an issue though that area is all pink.

The main thing that stumps me is that his top of his tail never looks like he has been scratching it. There is no broken hairs at the top of his tail or on the walls of his stall. I am not saying that he never scratches but....