I had issues at first. Both of mine turned their nose up at it the first time. The second time Roo tasted a bit, but didn't want any more. Pip still wouldn't try it. I think it was the texture possibly that they were unsure about. Now they absolutely LOVE it. They run around and vibrate with excitement while they're waiting for it. Go figure.
So... I would persist for a bit before you decide it's a definite no go.