Tail scratching after treatment...?

[Nudibranch]

The mare we bought recently had been treated for mites and had a bit of bare skin around her tail. She seemed to be scratching still so I treated her with the ivermectin which came with her. The scratching continued and after three weeks of ivermectin I then wormed her for pinworm. Still scratching! The vet agreed that it has become a habit now, and because she won't let the fur heal I'm sure it's probably still itchy so it's a vicious circle. She now has steroid cream but it has to be used sparingly so I am also slathering under and around her tail in Sudocrem but it makes no difference.

Has anyone dealt with this and how did you break the cycle? Her tail is a complete mess now, I'm almost tempted to clip the top off, it looks so bad!

 

[Jools2345]

IME pinworm can be hugely resistant to wormers, we had a pony at work with them and the vet had a concoction made up that had worming paste, steriod and something else, we used to have to smear round the horses anus with it twice daily for 2 wks, when the female pin worm comes out to lay eggs she comes into contact with it and it kills her and the eggs she lays, vet said often a second period of application is needed but we did not have a problem after the first. some people i know have just used worming paste and used it in the same way and found it has dealt with the problem. maybe speak to your vet about these options and see what they think

 

[Jenko]

it could be a SI injury or soreness, they rub/press their tails to relive discomfort and it scrubs the tails