Ah, the petplay. For reasons unknown this has always been close to my heart. I really didn't think it at first but it sort of grew into everything I do.
So, what do I like? I guess I am not one of those "hardcore" petplay doms, who force the slave to have a full transformation. I just like to reduce the slave down a notch. Just to deny her to be treated like a person. A pet - for me at least - represents a living being who I can take care of and who shows me affection without the need to speak. Maybe it's a way to make things simple, more easily to control. And also very amusing. It's a pleasurable sight when a slave gradually gets dehumanized and starts acting and thinking more like an animal. It's fun and entertaining even on non-erotic level.
However, the erotic part makes it even more effective. I get to constantly remind her that she is being treated like an animal... a lesser being. She gets her rights and privilidges stipped away and is completely under my whims. Of course, I want to be a good owner and take care of my pets. But just the mental state where she gets... Knowing that she is no better than a dog. And usually I can easily point out that she gets off from that. And tease her even more physically. The guilt of physical pleasure, the mental notion of being something less human, all of that just comes to one in proper petplay.
However, I am not into hardcore things personally. I don't require my pets to dress up in full puppy or kitten suit. I actually think dogs are kinda... meh. I like cats a lot more. Yet, I sometimes end up treating my pet like a dog instead of a cat. It's complicated. That's why I try and avoid using terms like "cat" or "dog"... And just generally talk about "pet", maybe "kitten" when I want to be affectionate. Cat ears and cat tail is a must though. And the tail... well, it should be one with a proper attachment piece. One that preferably viberates too.
Ok, so.... what I like doing with my pets? I do the normal stuff, I guess. Make the crawl on the floor, deny them from using hands unless absolutely necessary (they should use mouth instead), dressing them up next to nothing, making sure they don't jump on furnature, eat and drink from a bowl... And of course, if possible, use the outside as bathroom. But, since that is not always possible, I am filling to close my eyes as they head to the toilet to get relief. Like I said, I am not into hardcore stuff if it causes unnecessary difficulties.
With live-in pets... One thing I like to teach them is that they can show me when they are happy or want to "play" by nuzzling against my crotch or gently licking or kissing it. If I am in the mood, I can either do a proper playsession with them or just tell them to dig in and have fun. A good kitty always appreciates delicious "cream". And properly shows that.