Euthanasia of a Southern Koala at Ocean Park

Ocean Park is saddened to announce the euthanasia of a three-year-old female Southern koala ‘Merinda’ today, due to kidney failure brought on by an incurable disease known as oxalate nephrosis, which occurs in the South Australian population from where the koala originated. Dr Ian Hough, Veterinarian for the Cleland Wildlife Park in South Australia and veterinarians at Ocean Park made the recommendation during a recent planned visit by Dr Hough to discuss Merinda’s case. Merinda was euthanized at 11:46 a.m. today after several months of intensive care and treatment since April 2015.

Three southern koalas arrived in Hong Kong from the Cleland Wildlife Park in October 2014.  Two of the koalas, ‘Dougie’ (male) and ‘Yani’ (female), settled in well to the new habitat at Adventures in Australia and have remained stable. However, Merinda was later found to have calcium oxalate crystals in her urine samples, a symptom indicative of oxalate nephrosis.

Dr Hough, explained, “Although Merinda was asymptomatic at the time of her arrival in Hong Kong, oxalate nephrosis is a common disease among the koala population in South Australia and has been observed in koalas as young as less than two years of age. Ongoing research is helping to understand the cause(s) of the disease in koalas and it is possible that the low genetic diversity of southern populations may be a contributing factor. Oxalate nephrosis is a disease characterized by deposition of calcium oxalate crystals in the kidneys, which inevitably leads to renal (kidney) failure. The team here at Ocean Park have done a wonderful job of treating and managing Merinda for as long as they have done.” Dr Hough said.

Ms. Suzanne Gendron, Executive Director of Zoological Operations and Education, said, “The Park and Cleland Wildlife Park have been closely engaged since the koala’s arrival to provide the necessary husbandry and veterinary treatment for Merinda. Unfortunately, despite these joint efforts, Merinda began failing to respond to treatment and her health deteriorated to a state whereby a humane endpoint was reached. A humane endpoint is the earliest scientifically justified point at which pain or distress in an animal can be prevented, terminated, or relieved, while meeting the aims and objectives of maintaining positive animal welfare. After reviewing all options, the joint veterinary team decided that ongoing treatment would not be consistent with maintaining positive animal welfare and the most humane option was euthanasia. This decision is also consistent with the approved euthanasia policy of the Park and the Association of Zoos and Aquariums (AZA).”

“While the Park is deeply saddened for the loss of Merinda, we are supporting research in South Australia to understand this disease and will continue to work closely with Cleland Wildlife Park as we advance diagnostic techniques for this disease in South Australian koalas. In the meantime, necropsy and histopathology test results of Merinda will be analysed, which will contribute to our collective knowledge about the disease. Currently, the remaining two koalas at Ocean Park are in a stable condition and we shall continue to provide them with the best possible care,” said Ms. Suzanne Gendron.

The Hong Kong Agriculture, Fisheries and Conservation Department, respective Hong Kong Government departments and the South Australia Government were informed of the decision.

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