LOS ANGELES -- Fiona Apple is postponing her South American tour to be with her dying dog, Janet.

Apple says in a heartfelt, handwritten letter to fans posted on her website and Facebook page Tuesday that the nearly 14-year-old Pit bull is her best friend, mother, daughter and benefactor and "the one who taught me what love is." Apple says Janet suffers from Addison's Disease and is near death.

The singer writes, "I will not be the woman who puts her career ahead of love and friendship," and asks her fans for their blessings and patience.

Apple says she is staying home "and reveling in the swampiest, most awful breath that ever emanated from an angel" and plans to reschedule her South American appearances.