When someone says They fight like cat and dog!, it means that They fight for real. But according to some studies and also in my opinion I think that cats and dogs can be friends. So, if you love both of them, you may consider getting both of them. Just make sure you find the right dog breeds that get well with cats. Such dog breeds can be the Golden Retriever, the Bernese Mountain Dog, the Poodle, the Pekingese, the Pug etc.