We both survived the night, and Obie was neither better nor worse. Ted and I were waiting at the door as soon as the vet opened his office. My by-then hysterical diagnosis was aspiration pneumonia, because Obie's condition came on so suddenly. The doc considered the possibility, conducted the relevant assessment and examination, and said "Probably not. More likely upper airway inflammation. His lungs sound fine. He's not febrile. He might have picked up an infection, since he is an inside/outside cat. Let's try the least intrusive approach. Antibiotic and steroid injections and some subcutaneous fluid. If he's not better by tomorrow, or Wednesday at the latest, bring him back and we'll do some blood work and radiographs."
Ten minutes later, we were out the door. An hour later Obie was feeling better. He spent the rest of the day in front of a sunny window, sleeping some, eating a little, walking around some, watching his favorite toy dangle in front of him, but not going after it. He reminded me of somebody recovering from the flu--feeling good enough to sit up and take nourishment, but not ready to get out of bed.
Today, Obie's shed his pajamas and bath robe. He got dressed first thing and went outside with me to feed the horses. He's acting like his normal, annoying self. Sits in front of the computer screen so I can't see what I'm doing. Wants to be brushed, but then complains about it when it happens. Wants to be lasered, but then bites my fingers. Paws at and tosses papers out of my in-box to get my attention so I'll stop typing. Bats at my arm.
I'm glad to have him back.