The world's oldest female hippopotamus has died at Adelaide Zoo at the age of 49.
Susie, a crowd favourite at the South Australian zoo since 1975, passed away on Thursday after a battle with a number of age-related problems, according to Adelaide Zoo.
Zoos SA vet David McLelland told the ABC Susie was humanely euthanised this week.
"Over the past few months, Susie had been suffering from a number of age-related conditions which our veterinary team were monitoring closely and treating," McLelland said.
"Sadly, over the past few weeks, Susie's condition deteriorated and the veterinary team decided there was no further treatment that would improve her quality of life."
Adelaide Zoo boss Elaine Bensted said Susie had probably seen around 10 million visitors at the park since arriving from Sydney's Taronga Zoo more than 40 years ago.
"She really has been a part of our history," Bensted told Channel Nine.
On Facebook, Adelaide Zoo described Susie as "the oldest female hippo currently on record in the world" and said she would be "dearly missed by everyone who had the chance to work with her".
Susie is survived by her male partner Brutus who is now 52.
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