I would think you could use bio-oil on a horses skin. If we are able to use it then it should be fine for them. Or maybe look into WellHorse. Its a spray that I have used for a wound to reduce scarring. It might work for scar tissue as well.
Wow! Thank you I will look it up!
Depends on the thickness and cause of the scar tissue but a British cream called Camrose is excellent but it will take a few months of daily application to disappear completely.