Hi Maddy and Purplekat
I find this so fascinating. It would not surprise me in the least.
I can't say I ever noticed after scans, and didn't need chemo. But my neighbours black Lab came over and kept nuzzling my armpit whilst I was crouched hoovering out my car. I found a lump on that side not long afterwards! And I always felt my cat could sense when I was upset. She'd headbutt me - as if to say "Come on Mum, cheer up".
Hope you're both doing well
Might be the different smells - hospital smells in general, and they can probably smell the chemicals used. My cat has been a bit standoffish after treatment a few times, usually wears off after a couple of days (which is roughly how long it takes for the chemo drugs to leave your body)
I've just returned home from having a bone scan and our cat seems seriously spooked. He's scuttled round the edge of the room and shot upstairs.....has he seen the rays/felt different vibrations in the room/scented something strange? He's just gone back outside and avoided me like the plague!! 😾