The friendly Siberian is a naturally occurring cat breed that’s slow to mature, not reaching their full-grown size of 12–15 pounds (or more!) until around their fifth birthday. These large cats often like to cuddle and can be wonderful lap cats (although, of course, every cat has his own personality and preferences). Generally speaking, Siberian cats are bright, athletic, and get along well with two- and four-legged family members alike.  Our cats and kittens live with us in our home.  We have a little dog and many relatives that drop in to visit us with their dogs,  so our little felines are exposed to dogs of all sizes.  I am very diligent about litter training and while I have many kittens running around the house, I will also have as many as 9 litter boxes placed around the house so no one has to wonder where they can find the nearest place to relieve themself.  While this gets to be a lot of work, it is well worth it.