I see a lot of dogs in my typical workday. Some sick, some healthy, many somewhere in between. I remember some things about them after their appointments, but a few dogs are forever vividly etched in my memory. This is the case with Lucy, a 4 month old black Labrador mix adopted from a local rescue group.

Lucy was my 9:15 appointment on an early fall Saturday morning. She had been with her owners a few weeks, and was a typical happy, active puppy. She had received her first vaccination (DA2PP) four weeks ago while with her foster family. My physical examination was unremarkable – she appeared completely healthy.  So I administered her second DA2PP vaccination, the same product she had received a month ago.

Before I could withdraw the needle from her skin, it was apparent that something was very wrong. Lucy stiffened, and then collapsed. I immediately began treatment for this vaccine reaction, and she responded initially. She had her first seizure half an hour later. Over the course of the morning, her seizures progressed, and she stopped responding to the intravenous drugs we administered. She died at 2:16 PM, just over five hours after she bounced into the hospital, a bright, happy puppy with a tennis ball in her mouth.

My purpose in writing this book is to provide a straightforward explanation of what a vaccine is, how it works, and what ones are and are not needed for most dogs. I hope this guide helps you in making informed vaccine choices for your dog.