Lameness evaluation: Nerve blocks and Joint blocks
Our hospital facilities enable us to evaluate lame horses on a variety of surfaces both in hand and under saddle, allowing investigation of even subtle lameness. Once the horse’s gait has been fully evaluated, nerve or joint blocks are usually performed. This involves injecting local anaesthetic around nerves or into joints at various sites in the horse’s limb to determine the location of the lameness and narrow the area of interest.
If the horse ‘blocks’ (appears sound) after injection of the local anaesthetic, we can use our knowledge of anatomy to determine which precise structure or structures are likely to be causing the lameness. Sometimes, in complicated lameness cases, multiple limbs are evaluated concurrently. In addition, we sometimes see a partial response or improvement to a block, indicating that there is likely to be more than one site of lameness in that particular limb.
Once the site of lameness has been localised, we use diagnostic imaging to investigate the affected area. This targeted evaluation ensures investigation of significant lesions and avoids unnecessary imaging.
Diagnostic imaging used may include digital radiography (X-rays), ultrasonography and the use of Chiltern Equine’s in house magnetic resonance imaging (MRI) scanner. These state of the art imaging modalities facilitate specific and accurate diagnosis of lesions within the limb enabling us to advise on best course of action regarding treatment, prognosis and recovery.
Hyaluronic Acid (HY) has been used in horse with osteoarthritis (OA) for many years in combination or not with intraarticular steroids. At Chiltern Equine Clinic, we still use this product, particularly in high motion joints such as the stifle as HY improves the viscosity of the synovial fluid and helps joint function acting as a buffer and stabilizer of the joint synovial membrane. Furthermore, the drug has anti-inflammatory and analgesic properties due to increased joint lubrication, resulting in decreased pain in unstable joints.
Arthramid® Vet is used to treat non-infectious causes of joint lameness in horses, including both early and late stages of osteoarthritis (OA). Arthramid® Vet is a biocompatible, long lasting, non-absorbable, safe, non-toxic, non-pyrogenic, neuro-innocuous injectable polyacrylamide hydrogel. It consists of approximately 2.5% cross- linked polyacrylamide and 97.5% water for injection. It integrates into the joint tissue providing shock absorption to the joint. It is a good treatment option for horses suffering OA that is refractory to steroids, for those horses at high risk of laminitis (Cushing´s or EMS) or as a first line treatment given its promising results.
At Chiltern Equine Clinic we are very familiar with this product and we often use it in a variety of causes so please, do not hesitate to discuss with your vet all the treatment options for your horse.