Hi! It is not uncommon for orchids of many varities to lose the leaves on their older pbulbs; depending on their environment, they may keep them if they are happy, or they may shed them in order to divert energy to new growths. Just a question though - are you sure you have a cattleya? New growths on cattleyas are called psuedobulbs - whereas you called them "canes", which makes me think you may have a dendrobium. Just wondering
Cattleyas and dendrobiums are *very* different in their growing requirements, which is why I ask which one you have...and it is more common for dendrobiums to shed leaves on their old canes than for cattleyas to shed leaves from their old psuedobulbs. Maybe attach a picture to your next post and we can help you once we establish which type of orchid you have. ~Becky
EDIT: If you do in fact do have a dendrobium, the leafless canes can be divided and made into new plants. HOWEVER, I do not recommend this. You will get a bigger, stronger, more healthy plant if you leave the old canes intact. They serve as sugar storage for the plant even though they have no leaves. I strongly recommend leaving them alone. I know they are unsightly, but this is somewhat part of growing dendrobiums.
Just FYI, ideally, a "cutting" of a dendrobium should have 3-5 canes so that the plant has enough stored energy to recover. If you have a cattleya, you can also take cuttings of it, provided that the cutting has a minimum of 5 psuedobulbs, again to help the plant recover more quickly. Hope this helps!