There was great joy in the summer of 2018 when four cubs of an endangered tiger subspecies were born at Tierpark Berlin. Initially, the quadruplets developed normally, but in late 2019 veterinarians discovered that all four had knee misalignments, which caused mobility problems. Once this sobering diagnosis had been made, the tigers remained under close medical observation. A few months ago, the condition of two of the quadruplets worsened so much that, following discussions with the state veterinary office and vets at the Leibniz Institute for Zoological and Wildlife Research (IZW), Tierpark staff realised the kindest option was to relieve them of their suffering. In recent days, the condition of the remaining two quadruplets also rapidly deteriorated and they too have now been put to sleep.
“Tierpark Berlin has been committed to the conservation of the threatened Sumatran tiger for many decades, so today is a very sad day for us,” says Christian Kern, Zoological Director of Zoo and Tierpark Berlin. “Besides the fact that this species is critically endangered, we were also very fond of these tigers as individuals. Ever since we learned of their condition, we have been in close contact with scientists in Germany and abroad to discuss their health, possible treatment, and chances of improvement. In the end, we reached a point where we could do no more for the two remaining tigers except put them out of their misery.”
Sumatran tigers are some of the rarest cats on Earth; scientists estimate that there are fewer than 400 of them living in the wild. Individuals kept in zoos are therefore considered to be the last chance for the survival of this species.
In 2020, researchers established the probable cause of the quadruplets’ health problems. They believe it is a genetic condition passed down by their father Harfan, who has since died. As well as the knee misalignment that was initially diagnosed, the tigers were found to have various other musculoskeletal deformities. Following the diagnosis, vets closely observed the condition of the four young tigers, looking in particular for any signs that they were in pain. During an examination at the IZW, veterinarians found that the health of the remaining male tiger, Oskar, had greatly deteriorated. “Apart from the problem with his knees, we established that he had an inflamed jaw that hadn’t improved despite earlier treatment,” says Tierpark vet Dr Andreas Pauly. “We could only assume that this was causing him a great deal of pain.” Alarmed by that discovery, the vets decided to do a CT scan on the remaining female tiger, Seri. The results were distressing: along with her misaligned knee, Seri was found to have kidney disease. “The disease is incurable,” explains IZW pathologist Dr Claudia Szentiks. “Given her overall poor condition, there were unfortunately no treatment options.”
It was initially a joyous occasion when the Tierpark’s Sumatran tiger Mayang gave birth to four cubs in the summer of 2018. However, the euphoria was dampened when the cubs began displaying abnormalities in the way they moved. In late 2019, CT scans at the neighbouring Leibniz Institute for Zoological and Wildlife Research (IZW) confirmed that the four young Sumatran tigers all had knee misalignments that were damaging their cartilage and causing their hind legs to buckle when they walked. Despite various therapeutic approaches, no significant improvement was made. Given the quadruplets’ poor health, their mother Mayang (11) also underwent clinical and genetic tests last year. Fortunately, she did not show any signs of having a hereditary condition. Extensive analyses conducted at the Leibniz Institute for Zoological and Wildlife Research (IZW) and the University of Veterinary Medicine Hannover suggested that the cubs’ health impairments were inherited solely from their father Harfan, who died in September 2020. Following the deaths of the last two quadruplets, Oskar and Seri, Tierpark Berlin is now home to just two Sumatran tigers – their mother Mayang and her new mate Jae Jae.