A 12 year old Paint horse gelding presented to Cornell University Hospital for Animals for management of back pain and bucking under saddle. The referring veterinarian diagnosed impinging spinous processes (also known as "kissing spines") on radiographs. He was blocked with local anesthetics and injected with corticosteroids, resulting in a short, transient response (i.e. decrease of symptoms). The horse was referred to Cornell for a definitive diagnosis and treatment. On presentation the horse had pain on vertebral palpation of the dorsal spinous processes over several caudal thoracic vertebrae, and decreased dorso/ventroflexion of the spine was noted. A whole body bone scan was performed which revealed mild increased radiopharmaceutical uptake in several caudal thoracic spinous processes and mild increased uptake in the sternum. Spinal radiographs showed impinging spinous processes with moderate sclerosis in the caudal thoracic vertebrae. A cranial wedge ostectomy was performed on five caudal thoracic spinous processes in order to create space at the sites of impingement and pain. The horse was rehabilitated slowly over five months and then began working comfortably at all gaits under saddle, having an excellent long-term outcome.