Please try to avoid fresh water feeders for your Volian, try silversides on a feeding stick. Thaw the silverside place it on a feeding stick and wiggle it in front of your Lion.
When I feed my Lion I use a feeding stick because they have a hard time catching food, it can land on their head and they wont see it. LOL
One of the Lion I took in because the guy thought it was blind and could not see the food. I brought it home and used the Feeding Stick it ate without a problem.
What have you been feeding it?
How often have you been feeding?
Whens the last time this lion ate?