(AP) When people see celebrity animals on television and in movies, they may assume that the pets come from top breeders with pedigrees. However, most animal stars come from humble beginnings, says the Pittsburgh-bound author of a recent book on the topic.

Robin R. Ganzert, president and chief executive officer of the American Humane Association, says that about 80 percent of animal stars are rescued an inspiring message about compassion that she will share on March 27 in a presentation at Animal Friends, an Ohio Township-based shelter and adoption center. She'll be accompanied by Hudson, the golden retriever from the movie "Our Idiot Brother," and the dog's trainer.Ganzert profiles more than 20 of these performing cats, dogs, horses and other critters, along with their trainers, in her book: "Animal Stars: Behind the Scenes With Your Favorite Animal Actors," published in September by New World Library."It's a very important message to get out," Ganzert says about the potential rescued animals have.When Ganzert does one of her author presentations, she challenges people to "look at the other end of the leash" to learn about how these pets blossomed into the stars they are.People can learn from the trainers' "special techniques to make all of us better pet parents and just embrace and enrich the power of the bond," Ganzert says. Interacting with animals, she says, "just allows you to have a sense of empathy and compassion like no other."Animal Friends officials say they are excited to host Ganzert."This program is part of Animal Friends' ongoing mission to bring interesting and relevant companion-animal programming to our region," says Joanne Moore, chief programs officer. "We love offering a variety of opportunities that bring animal people together at our center."Other animal stars in the book include Finder, the horse who played Joey in "War Horse"; Hightower, the horse in "The Horse Whisperer" and "Runaway Bride"; Crystal, the capuchin monkey in "Night at the Museum"; and Kitty, the Burmese python in "Snakes on a Plane."Charlie, the second of two Himalayan cats to play Mr. Jinx from the "Meet the Fockers" movies, was found wandering the streets of Ontario before he found his loving home in New Jersey.For the movie "Hachi: A Dog's Tale" with Richard Gere, several dogs and puppies were needed to play Hachi at different ages.Ganzert joined the American Humane Association with its headquarters in Washington, D.C., and a film and television office in Los Angeles in 2010, after serving as deputy director of philanthropic services at the Pew Charitable Trusts, along with a stint at Wachovia Wealth Management. The association, which has been operating since 1877, works to protect vulnerable animals through programs and initiatives, including veterinary supervision of animals in films to ensure humane treatment."This is serious science," Ganzert says about training animals to act. "There are ways to train all animals safely."In Ganzert's presentation, Hudson will re-create some skits from his performances, namely the "Saturday Night Live" skit where Hudson serves as the angry dog that Mitt Romney tied to the top of a car."People love that," she says. "He's one of the best-trained dogs I think I've ever seen."