Summary
Equine musculoskeletal injuries, or other causes of reduced movement, can have a poor prognosis partially due to the secondary complications that may develop during recovery or rehabilitation. These can include supporting limb laminitis due to excessive weightbearing on healthy limbs and also problems associated with ventilation or perfusion due to prolonged recumbency. The risk of these complications is reported to increase with increasing body weight. While many methods have been attempted to reduce load and prevent complications, there is no current standard practice when managing horses with ambulatory difficulties. One critical consideration with load reduction devices is maintaining sufficient mobility to allow for blood flow and the prevention of muscle wasting. One of the most challenging obstacles with any weight reduction method or device is preventing pressure sores/ulcers or other tissue trauma because load is redistributed away from the limbs and onto regions of the body unaccustomed to weightbearing. Reported methods to aid in recovery and rehabilitation include rescue slings, forced recumbency, flotation tanks, water treadmills and aquatic therapy. While these methods have been successful in some horses, significant complications have also been reported. If too much weight is removed, muscle wasting or osteopenia occurs; conversely, if insufficient weight is lifted blood flow is hindered. The optimal load reduction is not known because each individual horse will have different requirements depending on the severity of the injury. The goal would be to restore normal weight distribution on the noninjured limbs, while supporting the weight that would normally be placed on the injured limb.