The kitty in the picture below there is suddenly very ill. The vet thinks it's a reaction to the inoculations they both received today. He has to be in the animal emergency all night so they can monitor his symptoms. He only weighs three pounds, so this is more of a danger, I suppose, than in a full-grown cat.
Meanwhile I'll be chomping TUMS and worrying over his health (and my husband will be worrying over our pocketbook).
Sigh. Gilda Radner was right: it's always something.