East West Equine Sports Medicine estimated that some 35,000 horses in the United States alone undergo general anesthesia per annum. Unfortunately, horses are at much greater risk of death when undergoing general anesthesia compared with humans, dogs, cats and other common domestic species. Over the past 25 years, several multicenter epidemiological studies have recorded the fatality rate and identified factors associated with the risk of death of horses undergoing general anesthesia. The mortality associated with anesthesia for healthy horses ranges between 0.12-0.9%. When systemically ill animals are included, the mortality rate raises as high as 3.4%. More than a third of these deaths have been attributed to traumatic events occurring during the recovery period. These injuries have been attributed to repeated and/ or uncoordinated efforts to stand.

To decrease the incidence and severity of complications during this critical period, and in an effort to assist and facilitate horses transition from an unconscious and recumbent state to a conscious and standing state, different methods have been developed. Data supporting any of these methods are scarce. However, fatalities are still reported with any of these methods. There is still no scientifically-based best practice for equine anesthesia recovery techniques.

Our group has developed a concept prototype in collaboration with the Sibley School of Mechanical and Aerospace Engineering (MAE) designed to assist horses in this transition. This prototype functions as a computer driven belay system exerting a constant tension to facilitate horses get up. Additionally, based on a series of built-in encoders (sensors), it can detect a fall and instantly apply a corrective force and, therefore, minimize trauma. A belt is attached to the horse through a specially designed harness. When certain thresholds for acceleration and velocity are reached, a motor applies a corrective, momentary and gradual pull, followed by a continuously variable belt resistance allowing for a controlled fall. The system tries to minimize the kinetic energy associated with a fall, therefore decreasing the potential for trauma as well as the potential for personnel injuries. We will leverage our early experience with this prototype to improve its characteristics and conduct prospective studies on experimental horses to better understand the mechanics of a fall and therefore intervene to prevent trauma. The aims of this proposal are to further refine our first working prototype and functionally test it in research horses.