Katherine A Miller & Liz Palika 
Animals at Work [PDF ebook] 
ASPCA Kids

Animals work hard to make ourworld a better place!Animals are so much more than companions-they make amazing contributions to the planet and to the human race. Here, you’ll learn about the dogs who are lending a paw to protect livestock, guide people who can’t see, pull sleds and wagons, and so much more. You’ll also get the scoop on the jobs other animals do, like horses who serve in the military and law enforcement, and even cats who control vermin and provide therapy to the sick and the elderly.Loaded with lots of color photos and friendly information you can trust, the ASPCA Kids books were written by animal lovers for animal lovers-just like you.