The veterinary approach to back problems

The purpose of this review is to outline current evidence for veterinary treatments of equine impinging spinous processes (ISPs), with particular focus on the decision-making surrounding treatment selection. Many horses have radiological evidence of ISPs, however this is often asymptomatic [1]. It should also be recognised that when obtaining radiographs horses are usually sedated, so their heads are lowered, thus the thoracolumbar spine is flexed and the spinous processes (SPs) are potentially maximally separated. When the horse is ridden the back will be in slight extension, and the SPs will be closer together. Nonetheless the presence of ISPs does not necessarily imply a clinical problem.
It is of note that relatively few professionally produced sports horses are presented for treatment of back pain due to ISPs. Either horses with ISPs do not make the grade in their athletic sport, or clinical signs associated with ISPs do not become apparent. This may be because with correct work such horses have excellent core muscle strength and are ridden in a ‘round outline’ by a rider who is in balance, so that the back is rarely over-extended. Even if there is a low-grade clinical problem, the horses can cope. It is only if the horse develops other problems, such as hindlimb lameness, that result in secondary back stiffness and or back muscle pain that the presence of ISPs becomes apparent. In that scenario radiographic examination may reveal the presence of ISPs, but they still may be of no major significance. Although the horse may compromise its gait and hold the thoracolumbar spine stiffly, resolution of lameness by diagnostic analgesia may greatly enhance back movement, indicating that the ISPs are not of clinical significance [2]. Alternatively clinical signs may become apparent if the horse is subsequently ridden by a less skilled rider, who is less able to ride the horse correctly in balance. The close SPs may become clinically apparent. […]