Moody discovered the condition after experiencing muscle weakness in his shoulder during a gym session, noting his symptoms are currently minor.
His diagnosis follows that of fellow rugby players Doddie Weir and Rob Burrow, who both died from MND in 2022 and 2024 respectively.
MND is a life-shortening neurological disease that affects nerves controlling movement, leading to muscle weakness and wasting, for which there is no cure.
A 2022 study indicated that former rugby players face a significantly increased risk of neurodegenerative diseases, including a 15 times higher risk of an MND diagnosis.