Black Spots and Shriveled Leaf on C. Little Dipper 'Sato' x Lc. Tropical Aurora 'SVO'
 

I recently purchased a Cattleya hybrid from an orchid greenhouse. I think it had some spots when I bought it but I feel like there might be more now. Also, yesterday, I noticed the smallest leaf was beginning to shrivel. I keep it on the top level of my indoor greenhouse closest to the light and water it whenever it feels dry. The situation is somewhat complicated because it does have two seed pods forming. I can attach more pictures if necessary. I have killed Cattleyas in the past but I am determined to keep this one alive!

It’s hard to tell from your pics, but could the small leaf just be developing purple pigment? The Cattleya that I have growing in high light areas have all developed this to some degree.

I also bought one with black spots. I didn’t notice them until after purchase. On mine they’re confined to the underside of the leaves. I assume they’re fungal. I grew mine on a windowsill in winter and moved it outside for the summer. They haven’t spread. Maybe make sure your gets good air circulation and the leaves stay dry? If they are a concern, maybe someone could provide recommendations on a good systemic anti fungal?

I don't think the leaf is developing pigment; it looks pretty shriveled and unhealthy. If you need a better picture, I can try taking one. What area of the plant?
As far as air circulation, there is a fan in the greenhouse that runs for about 15 minutes every hour.
Thanks.

The fan should run 24/7 to dry the plants, keep air from stagnating and to keep fungal spores from settling as easily. The spotting on the plant are small infections, probably begun when droplets of water were left standing on the plant in stagnant air.

Again, can't tell from the photo, but that look like a small leaf on an old growth to me. If so, don't worry about it.

Oh okay, I well keep it running all the time. The only reason I've been reluctant is because its a relatively small space, maybe 2 yards high with each shelf around 1.5 x 3 feet. I also keep other orchids and succulents in there, will they be okay with the fan 24/7?