Per The Economist: "The last pet-less leader in American history was Andrew Johnson, who left office in 1869 and is best-known for being one of only two presidents to be impeached (the other, Bill Clinton, had a dog and a cat). According to the Presidential Pet Museum, the White House has been home to over 300 animals, ranging from dozens of dogs, horses and birds to the occasional bear, tiger and alligator."
"Theodore Roosevelt had by far the most impressive menagerie: while in office, the famed outdoorsman and conservationist cared for some 50 animals, including a badger, a barn owl and a one-legged rooster. Although animals are beloved by Americans of all political stripes, their appeal in the Oval Office has not been quite so bipartisan: Democratic presidents have averaged six pets each compared with nine for Republican ones."
