Senior Horse Joint Health A Practical, Evidence-Led Guide to Supporting Ageing Joints Joint stiffness is rarely dramatic at first. It tends to show up quietly. A slightly longer warm-up.A moment of hesitation stepping downhill.A little less push from behind. For many horses over 15, some degree of joint change is not unusual. Degenerative joint disease (osteoarthritis) becomes increasingly common with age, involving gradual cartilage wear, low-grade inflammation of the joint lining, and adaptive changes to the underlying bone. The question...