I'm going to start breeding rats on a small scale, since my cat needs to eat more than just mice.

I was curious if Raimei, my unspayed female rat, is too old to breed for the first time. She was born at the end of August or early September 2012.

I wouldn't mind breeding her if its not risky because she has a great personality and she had never been sick... not even a slight sniffle out of her.