I used this as an introductory book, as it were, to animal ethics and theory in other books.
David DeGrazia, an authoritive author on animal rights literature, examines briefly three main issues that demand a reasoned perspective on animal welfare, and these are: animals for food (namely meat), keeping pets and zoo animals and animals research.
DeGrazia transcends over the two most principal ethical theories in this field: Utilitarianism and the "strong animal rights view" (mainly advocated by Tom Regan). He applies these theories to the areas in which animals are used above, and also uses the less used "sliding-scale model", a model which assesses the relative treatment of animals based on their cognitive, emotional and social complexity.
By doing so DeGrazia shows us that animals ought to be considered, and that there is more than one way of doing so.
Anyone interested in the animal rights debate, whether for or against, or someone endeavouring to start reading literature on animal ethics, you should read this book.