NO hoof-no horse: it’s an old adage but no less true for it. I learnt at vet school, but forgot and learnt again to my cost that the first place (and the second place!) to look for the cause of lameness is the foot. There is a broad principle that equine lameness (an abnormal stance or gait) is caused by pain, nerve damage or impaired mechanical function (sometimes a combination of all three).
In the hoof pain is invariably the main cause. So search for the source and treat it locally, but also be prepared to treat any more generalised problems (such as obesity). From bruising to infection (surface like thrush, burrowed-in as in abscess) to ever deeper trauma still (hoof penetrations); from laminitis to tumours (keratoma) to pedal bone disease – these all occur in the hoof. They all cause lameness that really matters to the horse and to you – lost days riding, lost days racing.