The research presents the development and testing of a Muscle Atrophy Scoring System (MASS) for horses, which provides a simple method to assess loss of skeletal muscle mass in horses, potentially helping to monitor horse’s performance and welfare. It was tested by three evaluators, and the results found that the system had a good-to-excellent agreement for ratings of neck, back and hind regions of horses, and was effective in examining associations between muscle atrophy scores and factors like age, weight, and pituitary pars intermedia dysfunction (PPID) status.

Development of the MASS

• The researchers embarked on developing a simple Muscle Atrophy Scoring System (MASS) for horses for the purpose of routinely monitoring their muscle mass. Currently available methods require expert knowledge and are often too pricey.
• They focused on providing simple, reliable measurements for evaluating skeletal muscle mass, specifically those relating to the neck, back, hind, and abdominal regions of the horse.
• The scoring system was tested in 38 horses of varying age, breed, and health status.

Evaluation & Testing of the MASS

• The testing of MASS was carried out by three evaluators. These evaluators rated the horses using the developed scoring system, and their ratings on atrophy scores were analyzed.
• The results revealed good to excellent inter-rater agreement for ratings on neck, back, and hind region’s muscle atrophy. However, the agreement was poor for the abdominal region, leading to its exclusion from further analysis.
• The study found associations between muscle atrophy scores with age, weight, and pituitary pars intermedia dysfunction (PPID) status, indicating the effectiveness of the MASS in revealing such relationships.

Potential Applications & Benefits of the MASS

• The research concluded with a positive outlook on the future application of MASS. It suggests that the MASS evaluations for the neck, back, and hind regions have an acceptable reliability.
• The researchers propose further evaluations to explore the potential benefits of the MASS in identifying and monitoring muscle atrophy in horses. This would provide a cost-effective, user-friendly option for horse owners, breeders and veterinarians to ensure the well-being and performance of horses.