I had the same problem with my fursona, Drako (He was a wolf), I created a new one "Axyz" (pronounced Axes, as in the plural of axis).
I felt awkward to just dump my old fursona, like it was nothing, but also made me feel odd to have two fursonas.
I solved it buy making Drako my fursona, but axyz his alias.
So basicly i kinda merged them, drako changed his identity and behaves as "Axyz" who in turn behaves like me, though some of drako's old traits resurface from time to time, so i didn't really lose him. Axyz just tries to repress his old drako traits.