Yes the book can be simple, but it explains everything you need to know, in simple understandable format. I got this book to refer to in my studies, it's great for a quick look up, although if you are wanting more info on an 'illness' then I would advise on a different book. The books that go into more detail can be expensive (around £60) but if all you want is the simple facts of what is wrong with you dog, or a back up of a sure visit to the vet, then I highly recommend this book.
The book was originally written in 1994, although it seems it has been amended in 2004, so everything should be correct. You can however tell it was written in 1994 with the pictures used etc, but none of that matters really in my opinion. This is like one of those 'Health Guide of Dogs for Dummies' books, but with a little more info.
For the price I would say it's just fine, and I wouldn't send it back. Any questions should more or less be in here with your typical dog case.