Dying cory?

[Scottishnewbie]

MY Venezuelian cory is spinning rapidly when swimming and then lying either on it's side or back for a bit then doing it again. What do I do? Water perimeters are good and I've just done another 50% water change.

 

[aaronalam]

Sounds to me like it's just its time, had it happen to me not long ago with a molly, same way as well.