Glad to hear that Chloe is feeling better. Last year when we took Rusty and Fluffy in for their shots, the next day they both were lethargic and touchy. Rusty, the mellowest cat in the world, growled at us. I called the vet and they said that in some cats it is a normal reaction. 24 hours later they were back to normal, but it scared the heck out of us for awhile.