Are there any medical risks associated with spaying cats in general?
There are more medical risks associated with not spaying. The only possible concern is the anesthesia, which is something your cat will come across anyway at some point. I would just ask your vet if there is a way to test in advance for allergies. But that’s extraordinarily rare, I have never heard of a cat having a problem after spaying.
Spaying is a very routine surgery, however all surgeries have risks. Anesthesia (spelling??) is a risk, but most vets know what they’re doing there. Infection is a risk after the surgery. I think spaying is worth the risk. Spaying keeps the pet population down (God bless you, Bob Barker), and also seriously decreases a cats risk for cancer. Go to a well-established vet if you’re really worried about risks.