Whole bay leaves are used for flavouring dishes but are removed before serving. This is done because the leaves are slightly toxic although you would need to eat a large quantity before you felt any ill effects
There are many plants toxic to cats. Below is just a few sites that list toxic plants. http://www.aspca.org/pet-care/poison-control/plants/plant-list-cats.html...
No, Cilantro is very fragrant and used as a primary spice element in dishes. Bay leaves on the other hand have a more subtle flavor and two or three leaves are added to soups and stews.