I love cats, in real life. In a game, cats, dogs, dragons, all fair game, no qualms. Maybe it's partly because I really can't do empathy, it's just not in me.
I used to feel really bad about it but, in the same way I can get over the horse in NeverEnding Story because I know the actual horse was fine, I recognise it's just bits of code on a screen. I'm playing a game that introduced a pet near the start and, when it inevitably died later, I wasn't sad. I was very much 1) disappointed that it went that predictable cheap-emotion route AND made my character directly cause its death by doing something I had actively avoided doing in this choice-driven game, 2) incredulous at the characters for making that dumb decision that was so obviously dangerous for the pet and going to end badly.