I got a kitten 2 days ago, and the first meeting between my dog and kitten was... all right; my dog was very caution and curious, which is understandable as she has never had a cat in the house, but she has never wanted to chase a cat outside. She's either ignored them or wanted to greet them.
However, today my dog has been whining and play bowing at my kitten, along with sometimes shaking while looking at her.
I don’t know if I should be worried or not?
This behavior is nothing to worry about. It's rather an expression of the dog trying to figure out how this newcomer reacts and how to communicate with them.
Dogs and cats have different body languages and a dog that has never interacted with a cat (besides chasing them) doesn't understand that language. Whining and play bowing are the dog's attempts to make the cat understand that the dog doesn't want to attack, but to play instead. A slight shivering can be a sign of nervousness or excitement.
Although this behavior is not aggressive or negative in any way, I would keep an eye on their interactions. Since the cat may also not understand the dog's language, it may feel threatened by the play bows and swat the dog. I would simply calm the dog down or call her back if she gets too excited. A great way to do that is to sit in between your cat and dog and pet both of them.
