Curious what you think. I have always thought this was really wierd about my SD's. Ever since they were school age and up they have had EPIC fights over....a cat. At mine and Dh's home we have 1 cat. She is somewhat affectionate but does not like to picked up or carried around. The skids have always made a beeline for her when they came over, screaming and grabbing for her so they could "claim her" for the next few hours. So, the cat learned to find hiding places that no one could find her in until they left. (I would bring her food & water and tell the kids they needed to leave her alone so she could eat. They used to say "Wow, your cat is so unfriendly. You must have not raised her right." To which I chuckle inwardly and say "Hmmm. I don't know. She is friendly enough to me. She sleeps next to me all night." 

At their BM's home, they have had several cats. Currently, they have 2 cats that are pretty tolerant to being man-handled and forced to sit on their laps for hours on end while they watch movies on tv. The SD's who are teens and 2 years apart will bargain with eachother for who gets to hold which cat for how long, etc. I kind of feel bad for the cats because they are just bargaining chips. Well, those cats are also so behaviorally challenged that they pee on couch, carpet, etc constantly. I think this is partially due to being manhandled and partially due to being left alone by BM, who doesn't like animals, when the skids are at our house. Previous cats have disappeared when the skids are on long vacations and BM claims she doesn't know what happened. I wouldnt' trust this woman with MY pets, that is for damned sure.

So, one day my Dh gets a call from one of the skids. Both SDs are screaming on the other end over.... you guessed it... who gets to hold the favorite cat at the BM's house. BM is gone, of course, and skids can't manage their own problems so they have DH referee. While he is on the phone, SD1 throws the cat at SD2's face. SD2 snaps and chases SD into the bedroom and is going to smack her.DH set them straight and told them how disappointed he was in their behavior, yadda yadda. I told them when they came over later that week that throwing an animal was completely unacceptable and if I EVER heard of this happening at our home, there would be consequences. This is not how we treat animals, EVER. 

I suspect that since their BM is emotionally messed up and is constantly out of the house when they need her, that the cats are a comfort-stand-in for their mom. This may be why they fight so vehemently over what seems like such a small thing, I feel bad for the skids and the animals that seem to run away, disappear, get "accidentally let out" by BM, and who learn to pee everywhere else but the litterbox to get attention or protest the nonstop attention they recieve. I can't do anything about that, except I have said NO when the skids asked if I would adopt one of their emotionally-messed-up cats because their mom decided suddenly that she wanted a new sofa sans the cat pee. I already have enough stress to manage at my house, thank you. I have tried to instill compassion for animals in my stepdaughters, but I still shudder sometimes at how much they see the cats as playthings to be bartered for or fought over. Have you seen any issues with animals and stepkids? I would think this would be a common issue when you have a biomom or biodad that doesn't model good behavior around animals.