If he gave you pre-loaded syringes (real syringe with needle on the end) then that makes sense as it wouldn't be labeled, though the receipt for the visit (might look like an office billing paper given when you paid for your visit) should at least state what was given i.e. antibiotics, ointment, etc..
Could have an allergy. Cage might need to be cleaned more often if there are infections on parts that usually are clean. Bedding and even dust can cause sneezing, running eyes, etc.. I'm personally not a fan of fleece as it gets filthy, fast, needing washed almost daily, and ALL the filth just clings to their fur to the point of discoloring. But even worse, is the chemicals from the clothing detergents can enter their blood stream. Since they self-groom, anything on their fur can be licked and absorbed. I read a report once about the chemicals that are being found in cats from self-grooming and it's jarring.
Point for the wild rant was it can be anything. It really helps if you can control their environment and limit their exposure to things that might be causing issues as it narrows the possibilities greatly.
