My 12 year old cat, Tweety, got her yearly shots and worming yesterday, and last night and today, she is sneezing and one of her pupils is slightly bigger than the other. They still dialate at the same rate, but the difference doesn't change when she is in different lighting. I seem to remember this happening before, but it went away soon after I noticed it, so I didn't worry about it. And she does feel puny after her shots usually, but she otherwise seems fine, and tonight is her usual self. Any ideas?