He was more concerned that the fox wasn't lazy and cleaned himself after eating than what he ate.
It wasn't a malicious act, why would he see it as something wrong?
But he was still a furry baby that required a lot of care., which BB gave him without hesitation.
Fun Fact: BB at this time usually removes the bandana from his neck on his rabbit form. It's not the best camouflage and without it, he doesn't stand out from other rabbits.
Since I hit a spot on the Kitty and Pupyrus's Chronology that I haven't draw and really want to do, let's pause it for a bit. (Doing some other stuff before I can draw it 💦)
For the same reason, finding that under all that dirt the cat was actually white was a big surprise.
Same with Sans discovering Pupyrus's spots on that famous first week.
PD: Sans calls Kitty "The Thing" from here to the end.
For the record, this was the first time Kitty had a bath since Pupyrus started living with Sans.
It's an old drawing, so it doesn't have the detail of how dirty the cat was. Just saying that the white fur on the image is a lieeee.