Horses are evolutionarily adapted not to show pain – the herd member who is seen by a predator to be weaker than the others is the one who is going to get picked off as dinner. When assessing behaviour problems, it’s essential to consider pain as a possible cause, but often difficult to recognise pain in such a stoical species. A professional clinical behaviourist will always get veterinary approval before they consult, to make sure any medical conditions are properly treated, but horses are masters at masking pain from vets too! In this article (below), behaviourist Sue McDonnell lists pain indicators that are useful when observing your horse’s behaviour. Remember being taught about “bridle lameness” back in the day? And traditional equitation in the UK teaches that when a horse carries its tail away from its bottom it’s using its back properly and engaging, but consider that there could be another reason for this. Also the glassy eye of the horse in pain, I’ve seen a lot of these both here and in working horses in the Middle East – a useful, if distressing, sign to be able to spot.