Pius IX. also had his pet - a superb "gatto soriano" (tabby cat - curator) which was always present at his frugal meals, sitting beside him, and claiming its full share both of food and attention. A very pleasant sight it must have been, to see this benign old pontiff taking his passegiata in the gardens of the Vatican, with Pussy sedately pacing at his side. When, after a while, the link of companionship was broken, and Pussy paced from this world to another, no pet succeeded him. "I am too old for new friendships," said his master; "moreover, death may come to me next, for my cat and I have both grown old in the Vatican."
--Eleanor Lewis, Famous Pets of Famous People (Boston: D. Lothrop Company, 1892), p. 177. Pius X was Pope from 1903 to 1914. I have not yet found any other reference to his cat.