He treats cats as prey, so with a high probability, the second pet will be slaughtered.
The breed is not recommended for beginners, animal training requires patience and experience, so it makes sense even for an experienced breeder to turn to the help of a dog handler who knows how to work with a Shiba.
The dog is independent, distrustful of strangers, keeps them at a distance, it needs time to get to know and accept a new person.