(CNN) -- The saga of Jack the cat, the lost pet that roamed New York's John F. Kennedy International Airport for weeks before being found last month, has an unhappy ending.
The feline had to be euthanized Sunday evening, American Airlines announced on Facebook, where the cat's plight has attracted thousands of followers.
"We are deeply saddened that Jack the cat has passed away, and we offer profound sympathy to Jack's owner, Karen Pascoe, for her loss," the airline wrote.
"From all of us at American, our sincere apologies to Karen and Jack's family and friends."
It was less than two weeks ago the airline announced that Jack had turned up in Kennedy's customs room after being missing for two months. The carrier originally described him as "well," but a health check revealed a number of problems.
"Jack had extensive wounds on the back of his body, and the wounds were unable to heal because his skin had deteriorated due to the malnutrition that occurred while he was lost," said Pascoe's friends in a post on "Jack The Cat is Lost in AA Baggage at JFK," the Facebook page devoted to the cat, which has more than 24,000 followers.
"Jack had been through so much, and the last thing anyone wanted was for him to suffer more."
The saga started August 25 when Pascoe was flying from New York to San Francisco with Jack and a second cat as part of a job relocation. But Jack escaped his kennel and was last seen at Kennedy's inbound baggage claim.
(A Department of Transportation Pet Incident Report released last month explains how it happened: A clerk placed one kennel on top of another on a baggage cart and the kennel on top fell. The impact "caused the kennel to separate," allowing the cat to escape.)
When a search failed to turn up Jack after a few days, Pascoe became frustrated with American and started the Facebook page "to help us put pressure on AA to step up their efforts." She also urged fliers to "do whatever they can do to keep their animals out of cargo."
The airline said it did everything it could to find Jack. While the cat was missing, workers placed food and water around the airport and set up humane traps. American even hired a pet detective and issued a pet Amber Alert in hopes of locating the feline.
When Jack was found, the airline promised to cover his veterinary bills.
The cat's owner hopes Jack's death will spur improvements in how airlines transport pets "so that no one else ever has to go through this again," her supporters wrote on Facebook.