Wd40 contains one of the same ingredients that DMSO does and with long term use can cause a build up over the horses preventing them to see and it cannot be corrected via surgery. Same thing goes for people because wd40 works wonders for people with arthritis but once again it cause a film over the eye cannot be corrected. So, yes it can have permanent long term affects that are not worth the risk. Wd40 can help when there is pain involved with the coffin bone. I actually went to a seminar in our area about wd40 and medicinal uses.