I have referred to this book many times and like the information presented. I believe this to be the 2nd edition. The 4th edition is currently available on Amazon. This is an excellent reference book with a lot of information. It might be wise to have a look at the review for the 4th edition which would have information about changes in veterinary medicine since this edition was first published in the 90's. Also, please keep in mind that if there is something seriously wrong with your dog, it is very important to get to your vet or the emergency clinic right away.