My Son's English Bulldog died of cancer a couple of weeks ago...he was 10 yrs. old...Then one of his cats, Lilly, was attacked and taken away by either dogs or coyotes...his one remaining cat, Tigger who was 14 yrs. old walked around lost amd moping for a week and then disappeared ...the last I saw here or anyone has was last Saturday she came to me and rubbed up against me and I petted her for a bit...then she was gone...We don't know if she died of a broken heart, went looking for her pal, Lillie or was also taken by Coyotes or wild dogs...So my son has lost all three of his pets in a month...he is taking it really hard...as we all are...so yes I have seen a cat mourn the loss of her pal and playmate first hand. I hope yours will be fine....