Catts are very resilient plants. I have 2 in particular that had all their roots removed. One, that I believe was brewing with rot when I took it home and the other that I think I overwatered. It was my first orchid and I never had inspected the roots until I began researching the steps involved in caring for them. They're both now doing better than I expected for such a short time since I performed surgery on them.
4 new ps.bulbs on one, and 3 on the other, so far!
Read these following threads. I suggest you follow the recommendations in them. Best of luck with your orchid.
Cattleya Crisis AGAIN! Hold The Laughter...please