Yeah, like everyone else said, you can have as many fursona as you'd like.
The usual lingo I use is that you can have multiple characters of which you like to play as, and your "fursona" is the main one you prefer to go by and pretty much represents YOU.
I have multiple characters I like to play as from time to time when I feel like trying something new. These are usually story characters who I pretend to be in the shoes of so I can get a feel of how their personality should be.
My fursona, Lita is the special, main character; she's the character that is pretty much ME. She is a representation of me, when I act online I imagine myself as her, and I use her and her name on nearly every site I sign up on.
It is possible to have more than one
fursona, but I often find that difficult and prefer just one.