Originally Posted by HagonNag
Sometimes horses get pinworms just like kids do...and I don't think any of the regular wormers work on them. They will cause horses to itch and rub against fences, stalls, whatever until they are almost hairless. I'm sure there's an answer... you could google pinworms in horses or ask your vet. I can't remember what works on them. Good luck
Pyrantel pamoate treats for pinworms. To the OP- what dewormers have you tried and with what frequency?