Diagnosis of sub-performance due to lameness

Orthopaedic conditions are the most common cause of poor performance in sport horses and as such the management of these is a critical part of optimising performance. It is important to ascertain if there is actually poor performance or just an inherently low level of performance. The expectations on the horse may be beyond those of the horse’s actual athletic capabilities or that of the rider. There are differences in presentations for different levels of rider experience and competence. Many amateurs will present horses as a poor performance case whereas professionals are more likely to present them as a lameness as they are capable of riding the horse through many more painful and schooling issues.

Common causes of poor performance in sport horses is usually related to proximal suspensory desmitis and sacroiliac region pain, joint pain and back pain. In young thoroughbred racehorses, fetlock and carpal pain are more common.

An accurate diagnosis is essential to treat any cause of poor performance effectively. It is very easy to fall into the trap of using random speculative medications at the request of the rider or trainer. Trial medication can have a role in the assessment of subtle conditions, so that the response to can be assessed in normal work over a period of time, but assessments need to be as objective as possible, as it is easy to fall prey to a placebo effect.

Diagnosis relies on trying to obtain an accurate history in the first place. Many riders may just describe the horse as “not quite right” or “not jumping right”. Others will provide an overly extensive of history of every problem the horse may have had or is thought to have had. Try to summarise this down to a few bullet points of the key problems. Beware riders trying to give a history that fulfils their preconceptions of what the problem may be.

The clinical examination is very important but in the majority of subtle cases there are no significant clinical findings. However, in some cases it is amazing how obvious findings can be missed in the desperate search for something obscure, and riders are often confused about which leg the actual problem may be affecting. A dynamic evaluation is very important and horses should be lunged on a hard and soft surface as a differentiation between these two is often very helpful. Flexion tests can be helpful but I rarely rely on them. Ridden evaluation is critical to try and accurately identify the problem as perceived by the rider in more subtle cases. It is quite common for a horse to demonstrate a mild forelimb lameness when lunged on a firm circle with the blocks to the feet but this may not be the actual cause of poor performance under saddle. Thus riding the horse when blocked can be very helpful to see if it actually improves the perceived problem. However, there can often be a placebo effect with the rider and thus I try and do this ridden blocking with the rider not knowing which areas have been blocked. It may also be difficult for riders to feel an improvement and thus having the horse also ridden by another experienced rider can be very helpful to accurately interpret the results. A thorough and logical progression of diagnostic local analgesia should be undertaken. High yield areas in cases of poor performance are the proximal suspensory ligaments, sacroiliac regions and stifles.

After accurate localisation of the problem then diagnostic imaging of the affected areas would be undertaken, predominantly with radiography and ultrasonography. MRI examination can be very helpful particularly for feet but also in other areas if there is a lack of significant findings on two dimensional imaging. I rarely use gamma scintigraphy in poor performance cases in sport horses, although it is extremely helpful in subtle problems in young thoroughbred flat horses with their active bone turn over.

Once a diagnosis has been made then a treatment plan can be constructed containing the horse’s athletic targets and the severity of any pathology that has been identified. As mentioned earlier the response to treatment can be very helpful in determining which of any abnormalities noted are the most significant. There are often multiple concurrent sites of pain, and treating all of these in sequence, alongside a progressive rehabilitation programme, will be most effective.

Andrew P. Bathe MA, VetMB, DEO, DipECVS, DipACVSMR, MRCVS

Andy qualified from Cambridge University Veterinary School and subsequently trained in surgery at the University of Bristol and then at Rossdales in Newmarket. After working as University Equine Surgeon at the Queen’s Veterinary School Hospital, University of Cambridge he returned to Rossdales, where he became a partner and, in 2021, a clinical director. Andy’s main areas of speciality lie in orthopaedic surgery and lameness, especially related to competition horses. He has always been interested in the application of novel diagnostic and therapeutic techniques to lameness problems and poor performance. He is a Diplomate of the European College of Veterinary Surgeons and holds the Royal College of Veterinary Surgeons (RCVS) Diploma in Equine Orthopaedics. He is recognised by the RCVS as a Specialist in Equine Surgery. He is team vet to the Japanese Three Day Event Team. He has previously been team vet to the British Three Day Event and British Pony Showjumping Teams; the Japanese Showjumping and Dressage Teams; the Hong Kong Dressage Team; as well as working for numerous private competitors at competitions and championships. He was an official treating vet for the 2012 Olympics in London. In 2015, Andy was awarded Diplomate status by the American College of Veterinary Sports Medicine and Rehabilitation (ACVSMR), which means that he now holds diplomas in three separate areas of expertise (surgery, orthopaedics and equine sports medicine). He is a Board Director of British Showjumping. He enjoys skiing, ski mountaineering and racing cycling in his spare time.