Bob, the seven-year-old two-toed sloth, had to be put down on Monday due to medical reasons, the Toronto Zoo said.
The sloth was born at the zoo on June 18, 2011 and was moved from the Kids Zoo to the Americas Pavilion in April 2017.
In a Facebook post announcing his passing, the Toronto Zoo explained their decision to humanely euthanize the animal.
The zoo said that the sloth had lost his appetite over the past few months and had “lost a significant amount of weight.”
“Bob was admitted to our Toronto Zoo Wildlife Health Centre on Sept. 7 where he received intensive supportive care as a last effort to try to get him better. Many diagnostic tests were performed, including repeated ultrasonography, radiography, blood and urine analysis, and a CT scan,” the zoo said in the online post.
“Despite all of the efforts of the Wildlife Care and Wildlife Health staff, he deteriorated quickly over the past couple of weeks.”
Wildlife Health Care staff made the decision to put the sloth down after consulting with veterinarians at other zoos as well as university researchers.
The zoo said that a post-mortem examination confirmed that the sloth was suffering from “severe and irreversible soft tissue mineralization and osseous lesions.”
Samples are being sent to the University of Guelph for further examination.
In response to a comment in its Facebook post, the Toronto Zoo said the young sloth may have suffered from an “excess consumption of vitamin D,” which possibly was a factor in his deterioration.
The zoo said it suspects that the sloth, who shared his enclosure with a marmoset, may have consumed part of that animal’s food source, which contains large amounts of vitamin D.
“Bob will truly be missed by all zoo staff, volunteers and the many guests over the years who had the opportunity to meet him,” the zoo said.
