I had my 4 year old CAG rescue for about six months before I brought home a tiny stray kitten. The bird was used to dogs (previous home) so a cat was no thing. What you have to worry about is the cat attacking the bird. If you get a kitten you can raise it up to know that if it messes with the bird, there will be trouble. I used a spray bottle to accomplish this and also, when the kitten was still small, I let him swat at my grey so he could learn a lesson, and he did when the grey bit his paw HARD. You can never trust them alone however as the grey might tease the cat as mine does.