Fun, thanks! Got stuck on 1A/1D for a second, as I hadn't heard of 1D before and kept think "specialized words" in 1A meant it could also be parsed as 2 words.
Fair enough… CATIO was definitely a "I need to make this grid work" (and every time I'd ever seen it my reaction was "Is this really a thing? People are crazy about their pets").
Oh, I actually like CATIO as fill, it’s a great word that you can figure out even without knowing it beforehand. And the cluing for 1A has a nice parallelism, just tricky for me (in a fun way!)