started Prascend now Sidewinder.

My Horse was recently diagnosed with Sidewinder. She is 32 years old and was put on Prascend last July. She was fine and sound at that time but the vet though it would help her with lameness issues in the future. She became very lame in Mid-November. I am wondering if this sudden extreme weakness lameness in the hind end could be a side effect from the Prascend. Does anyone else have a horse who was diagnosed with Sidewinder within 6 months of starting Prascend? Justing wondering if there could be a connection.