by Ben Sturgeon, Bsc, BVM&S, Cert EP, MRCVS
When presented with a lame horse, the wisen among us should ascribe the differentials fall into one or more of three categories. Lameness due to pain, due to a mechanical interference, or lameness due to a neurological deficit. This is quite correct and will diagnose the vast majority of diseases affecting the back such as overriding dorsal spinous processes (kissing spines), abnormal saddle fit &/or rider position, and cervical malformation or instability (Wobblers) respectively. But, with back pain in horses presenting with a myriad of subtle signs from lameness and lack of hind limb impulsion, a dropping of performance in any and many disciplines, a change in attitude or behaviour, to loss of top line or tying up and girthing pain to name a few. The variety of possible presenting signs means that for full evaluation, we need to add a few other “lameness” associated categories; namely primary muscular disease, primary gastrointestinal disease and even ovarian and testicular/scrotal disorders to fully consider and elucidate a horse with apparent back pain.
Firstly however, we must mull over the commonalities. Ill fitting tack, poor rider position, bilateral fore or hind limb lameness are often precipitating factors and must be addressed along with or before any significant consideration is given to or of primary back pathology.
Secondly, with careful observation, palpation and clinical examination elucidation of areas of the spine to concentrate on can be devised. Cervical for Wobblers, thoracic and thoraco-lumbar for kissing spine, facet joint osteoarthritis and supraspinous ligament lesions, the sacro-ilium and pelvis for sacro-iliac ligament desmitis, osteoarthritis, pelvic stress fractures, iliac artery thrombosis and finally ovarian tumors, scrotal contusion and adhesions.
It is perhaps then unsurprising to find or to expect that full evaluation of a horses back is rarely achieved in a single session but over a period of examination days. Equally this will involve several complimentary techniques; imaging protocols including radiography, ultrasound and often scintigraphy (bone scans) in combination with nerve or joint blocks or with simple anaesthetic infiltration into an area such as the sacroiliac joint or where questionable vertebral dorsal spinous process changes are seen.
These techniques largely provide a diagnosis and framework for treatment. For osteoarthritic conditions, infiltration of corticosteroid, use of reparative and retraining physiotherapeutic and riding tec hniques usually results in a good prognosis for a full return to work. Shockwave for ligamentous disease and the implementation of biologic (stem cell) therapies is currently in vogue and also provide favourable results along-side rest and a scaled return to exercise. B Occasionally surgical debridement of an area is required where conservative treatment has failed but is less common, has implicit complications, requires a substantial period of lay off and is less common. Again for most techniques, consideration of the exercise programme, developmental exercise techniques in combination with bioanabolics and local or systemic analgesics will result in good returns to performance. Importantly, it is vital to emphasise that very often, horses require ongoing evaluations during the rehabilitation phase. If painful or inflamed areas continue to cause distress or altered mechanics then the rehab will prove limited and further therapy is required. Equally, it is not unusual to identify second areas of pathology, not necessarily confined to the back, but in the limbs which become more evident as the back pain recedes and may in fact be the be the primary cause of the presenting back issue and so require equal attention. Bone spavin, stifle pain, suspensory desmitis and heel pain are all common findings in such cases.
It is important then to continue to have an open mind in a horse with back pain, to continue to involve your vet in ongoing and future evaluations, to expect further treatments and to also understand when new areas are highlighted for investigation, evaluation and treatment. It is important fundamentally to recognise that the vast majority of horses presented for back pain have more than one problem.
Lastly, as highlighted, horses presented for back pain may not necessarily fall into the identified musculoskeletal categories of pain, neurological or mechanical dysfunction, medical causes are also recognised. Perhaps the two most important are muscular disease and gastro-intestinal disease. Whilst primary muscular disease is less common, rhabdomyolysis, either recurrent and associated with exertion or, obviously, not associated with exertion (such as polysaccharide storage myopathy) should not be discounted. In both cases horses may present with poor top lines (and usual saddle area pain as a result), loss of performance and sub-clinical disease precipitating a lengthy investigation into the back. However, exercise testing with biochemical parameter assessment may be wholly appropriate with consideration of the horses’ diet, stabling and exercise management being vital to address before seeing significant improvements. Just because your horse is not a Quarter horse or Draft does not preclude the possibility as Thorughbreds and Standardbreds are well represented in the conditions. Equally many pleasure horses are diagnosed with gastric ulceration, often at the pylorus, or exit of the stomach into the small intestine, where the action of tightening the girth produces a pain response often misinterpreted as a cold back. Again the symptoms of gastric ulceration can be vague from simple poor performance to weight loss, cribbing and wind sucking, and change in faecal consistency. Here, gastroscopic evaluation of the horses’ stomach is necessary for assessment followed by an often prolonged course of acid suppression treatment in combination with dietary and pasture management and simple exercise protocols to prevent recurrence.
For fear of sounding sanctimonious back pain can be extremely rewarding to investigate, diagnose and treat. Many horses live with owner ignorance or worse benign neglect and acceptance that their horse has a sore back where consideration of facets of management along with relatively simple therapeutic protocols can completely transform a once, has been, nag into a born again superstar.