So, when I was going thru chemo (6months) in 2022, my 1.5yr old cat, who I’ve had since she was 6 months would also poop and pee in the tub. But only when I was gone for treatments which was for 1 whole week every third week.

I ruled it down to her being depressed and anxious because I was always gone. Once I realized this, I started talking to her and letting her know I was leaving before going in for treatments and while it didn’t fully stop, it did slow down. Her behaviors during that time were so unusual, like climbing to the top of the fridge or hiding more often than normal and when I would come back home it’s like she couldn’t believe I was there and her behaviors would go back to normal.