President George H.W. Bush had a problem so important he sent a memo to White House staff asking them to take a pledge. His dog, Ranger, was packing on the pounds."WE AGREE NOT TO FEED RANGER. WE WILL NOT GIVE HIM BISCUITS. WE WILL NOT GIVE HIM FOOD OF ANY KIND," the pledge read.Bush ends his memo saying, "I will, of course, report on Ranger's fight against obesity. Right now he looks like a blimp, a nice friendly appealing blimp, but a blimp."That memo, along with countless anecdotes and more than 200 pictures are featured in Dallas author Jennifer Boswell Pickens' new book, Pets at the White House, which gives readers a glimpse of what life is like at 1600 Pennsylvania Ave. for pets, and what those pets have meant to their famous owners."I think they all would agree 100 percent that they got a lot of comfort from their pets," Pickens said.The coffee-table book devotes a chapter to each administration's pets from Kennedy to Obama. And an introduction gives an overview of the animals that were part of first families prior to 1961, including the varied assortment of pets cared for by Calvin Coolidge and his family, including Rebecca the raccoon, which walked on a leash."They became such known pet-lovers that if you no longer wanted your pet you could just ship it to the White House and they were known to keep it," Pickens said of the Coolidges.Photographs include first daughter Caroline Kennedy perched on her pony Macaroni on the White House's South Lawn and the elder Bush walking across the same lawn with brown-and-white springer spaniel Millie as her puppies trail behind them.Pickens also gives readers a variety of anecdotes about first pets. She writes that Franklin D. Roosevelt's Scottish terrier Fala traveled with him, attended galas with world leaders and even contributed to the war effort by giving up toys for a scrap rubber collection campaign.When the Kennedys were given a dog by Soviet leader Nikita Khrushchev, Pushinka -- Russian for "fluffy" -- underwent tests at Walter Reed Army Medical Center to rule out everything from listening devices to bombs.One of Millie's puppies, Spot, was a resident of the White House twice. After being born there, she went to live in Texas with George W. Bush and Laura Bush before returning when he was elected president.Former first lady Barbara Bush writes in the foreword, "Not only are these animals important to each first family, but, as George points out, when you have the toughest job in the world, there is nothing like the unconditional love of a dog."Or a cat. Amy Carter, who was 9 when her father became president, says in the book, "Misty, my cat, was one of my best friends and she really turned the White House into a home."Not long before her death last year, Betty Ford commented for the book that the family's golden retriever Liberty was her husband's "favorite adviser."'Almost mandatory'Inspiration for a book focused on pets came as Pickens was putting together her first book, Christmas in the White House, which came out in 2009. Pickens, who worked as a staffer in the Texas finance office when George W. Bush was running for re-election and has worked as a consultant on various campaigns, turned to presidential libraries, old newspapers, first families and White House staffers as she put the book together."I think a lot of people have their own pets and a lot of people find comfort with their animals," said Pickens, who lives in Dallas with her husband, four daughters and two dogs.Historian Douglas Brinkley of Rice University notes that it's "almost mandatory" for first families to have a pet, adding, "We demand a first pet.""So many Americans have dogs and cats and it makes us feel like the first family is one of us," Brinkley said.The public fascination is shown in the book, too: There's a photo of a greeting card featuring the Clintons' first cat Socks, complete with a paw print "signature," a photo of Laura Bush holding Scottish terrier Barney eyeing a chocolate replica of himself and a picture of cookies being decorated depicting Bo, President Barack Obama's Portuguese water dog.Anita McBride, Laura Bush's chief of staff in the White House who currently teaches at American University, was among former staffers interviewed for the book. She notes that it was Barney that "opened up the White House to the public" after the Sept. 11 terrorist attacks. With a tiny video camera on his collar, he helped record a tour of the White House's Christmas decorations. The Barney Cam was such a hit that it continued for the next eight years."The pets really were a big part of helping to tell the story of life in the White House," she said.