Ep. 47: Decoding Muscle Myopathies Part 1: Understanding RER, MFM, MFM-ER, MFM-WB, PSSM2-ER;

Join Jill and Clair as they delve into the complexities of equine muscle myopathies, specifically focusing on what was once known as PSSM Type 2. In this multi-part series, they are joined by Dr. Katie Young, a leading equine nutritionist with Kentucky Equine Research. 

Together, they: 

- define all the relevant terminology

- unpack the differences between PSSM Type 2, Recurrent Exertional Rhabdomyolysis (RER), and Myofibrillar Myopathy (MFM) in both Arabian and Warmblood horses. 

- learn about how the various conditions are diagnosed, including genetic testing and muscle biopsies, 

- discover why accurate diagnosis is crucial for effective treatment

- learn what exactly is going on in the muscles of horses diagnosed with these conditions.

Whether you're an owner of an athletic horse or simply interested in equine health, this series provides essential insights into these challenging conditions.

Additional information - Equine Neuromuscular Diagnostics Lab Resources

Glossary of terms discussed in the episode:

Exertional Rhabdomyolysis (ER -) - “tying-up” associated with exercise that causes a syndrome of muscle pain/cramping and damage to muscle tissue

Type 2 Polysaccharide Storage Myopathy (PSSM2-ER) - the form of PSSM that causes elevated muscle glycogen but that is not caused by the GYS1 mutation. It is brought on by exercise and results in elevated muscle enzymes and is now termed type 2-ER (PSSM2-ER).

Recurrent Exertional Rhabdomyolysis (RER) -  is an intermittent form of tying-up in horses the cause of which appears to involve an abnormality in intracellular calcium regulation.

Myofibrillar Myopathy (MFM) -  a new disease previously categorized as PSSM2, particularly in Arabian and Warmblood horses, is a genetic condition that describes abnormal build-up of desmin in muscle tissue.

Myofibrillar Myopathy with Exertional Rhabdomyolysis MFM-ER - Myofibrillar Myopathy associated with exercise and elevated muscle enzymes found in Arabian Horses

Myofibrillar Myopathy without Exertional Rhabdomyolysis MFM-WB - Myofibrillar Myopathy that does not result in elevated muscle enzymes. Associated with exercise intolerance predominantly in Warmblood Horses

Do you have questions about feeding your horse? Contact us at [e-mail]

Thanks for riding along with us!