Blade Runner (Do Androids Dream of Electric Sheep)

In this novel, I find the emphasis on animals to be very strange.  In the first chapter, Rick Deckard is distressed about the death of his sheep, and so he decide to buy an electric sheep.  Everybody in the apartment building owns an animal that lives on the roof.  I was very confused by this focus on animals.  However, throughout the following chapters, the animal obsession is discussed more and the reader starts to realize why these people are so infatuated with animals.  Sheep, horses, ostriches and dogs are some of the animals that are mentioned.  They are a sort of status symbol, and the larger they are the better.  Rick goes to a pet store and wants to buy an ostrich displayed in the window.  The conversation between Rick and the animal salesmen makes it seem like there is some sort of secret market for the buying and selling of animals.  Trading animals is briefly discussed and Rick makes a sketchy phone call.  I am interested to find out more about this emphasis on animals.  I am still a little confused by the whole thing, but I'm sure that as I read on it will be further explained.