Zippy has gotten noticeably worse over the last couple of weeks; and today he was squeaking overnight, squeaking in the morning, squeaking when I got home, and was basically unable to walk. So: the time has come, we'll make an appointment for Saturday.
Which explains what my brain chose as today's soundtrack: a K-pop song that I'm only tangentially familiar with called "Cry, Cry". It seemed like a bizarre choice this morning, but thinking about the title, and realizing that one of the few lyrics in English reads "Can't you see the look in my eyes?", the message my brain was sending me is clear. (Reading a translation of the lyrics, it's of course about something completely different.) I actually think Zippy isn't feeling too horrible right now, but we don't want to wait until he's in agony.
He will be missed. Very much.