Via White House Pets:
Caroline Kennedy's pony, Macaroni, was a present from Lyndon Johnson. Macaroni roamed freely around the White House grounds and received thousands of fan letters from the American public. Caroline also had a famous dog named Pushinka, who was given to her by the head of the Soviet Union, Nikita Khrushchev.
Amy Carter had a dog named Grits and a Siamese Cat named Misty Malarky Ying Yang.