Category: Animals
Published on: April 8th, 2026
We are devastated to announce the loss of our eight-month-old Amur tiger, Ozo, who died suddenly from a congenital heart defect on 7th April 2026.
Ozo was much-loved by keepers and visitors alike, as well as by his mother, Yuki, and sister, Akira. During his short time on Knowsley’s Tiger Trail, Ozo quickly became known for his curious and playful nature endearing him to all who watched him grow.
Ozo’s keepers and the wider team at Knowsley Safari are deeply saddened by his sudden passing. He will be hugely missed by everyone who had the pleasure of meeting him.
Q&A
We understand that people may want more information about the unfortunate loss of our Amur tiger, Ozo. We hope the following information helps provide some clarity and reassurance.
Ozo was undergoing investigation of some abnormal breathing that had been picked up by his keepers. Very sadly he stopped breathing under anaesthetic, and despite the efforts of our keepers and veterinary team, passed away.
No, we did not, but the keepers had observed his abnormal breathing, and that he was noticeably smaller and less energetic than his sister. This led us to investigate further.
Unfortunately, as is also the case with many humans who have similar conditions, there was no indication that anything was wrong with his heart, and it would not have been possible to detect the heart defect in advance.
Yes, a post-mortem was carried out that revealed that he had a severe congenital heart defect, which was why he reacted badly to the anaesthetic. Congenital heart defects are due to the heart developing abnormally during pregnancy, and are present from birth. When Ozo was younger there were no visible signs, but as he started to grow up, his keepers had picked up on his abnormal breathing, and that he was noticeably smaller and less energetic than his sister. As he grew up this would have got worse, and over a very short time would have developed into heart failure.
It is a structural defect of the heart. The development of heart defects and other congenital abnormalities is complex, and related to both genetics and external environmental factors during pregnancy, as well as random mutations. It does not mean that we shouldn’t breed from this pair again, or that Akira is also going to have problems.
Very sadly, there was nothing our highly experienced veterinary and animal care teams could have done. The defect led to sudden heart failure and could not have been treated or prevented.
No. Congenital heart defects are not considered common in Amur tigers.
Yes. This type of defect would have had the same outcome regardless of whether Ozo was at Knowsley Safari or living in the wild.
Congenital heart defects are not always inherited. As a precaution, we are closely monitoring Akira, as well as her parents Yuki and Makari, to ensure they continue to receive the very best care and attention.
Just as we always do, we will continue to provide a high quality, varied diet, enrichment activities that encourage natural behaviours, and regular health monitoring by our expert teams.
We remain committed to the European Amur tiger breeding programme, however, the welfare of Yuki, Akira and Makari is our current priority.
