While this book was the "breeder's Bible" when it was first published 25 years ago, the fact is that genetics, especially equine genetics, has progressed by leaps and bounds since then. Many things we thought to be true then are no longer so. I think this is a great book to have in your library; some things about it are timeless. However, if you're looking to answer specific genetic questions (For example, "How do I get an Overo?"), then you may end up with wrong information. Anyone using it to answer these questions would do well to double-check it with another, more recent textbook, such as "The Genetics of the Horse."