We thank Ms Josephine Lew Wei Ling for her letter (Don't love Inuka to death; April 22).
Inuka is dearly loved by all of us at Singapore Zoo, particularly the keepers and vets who care for him daily.
At 27 years, he has outlived the lifespan of polar bears in the wild by more than a decade. But his health has been on the decline because of his age.
For the last five years, he has been under our senior animal care programme designed to ameliorate the effects of ageing.
We have modified his care routine, changed his diet, administered joint supplements and conducted regular health checks.
In the last two years, we also placed him under an increasing regime of pain management for arthritis.
Despite our best efforts, his age-related ailments have significantly worsened in recent months, eroding his quality of life.
In the last physical examination, the zoo vets found additional problems.
Due to his ailing limbs, he is unable to properly support his weight of more than 500kg. As a result, he drags his feet, and this has caused ulcerations on his pads that have led to deeper infection between his toes.
He also has a wound on his lower abdomen, likely caused by urine burns from incontinence and recurring urinary tract infections.
While the pain and discomfort from these conditions can be partially managed with drugs, prolonged use of the drugs may render them ineffective and could also lead to undesirable side effects, such as kidney and liver failure.
In caring for our geriatric animals, our priority is to ensure they have an acceptable quality of life, which we monitor and evaluate closely based on a comprehensive welfare assessment framework.
We will be conducting another medical check-up for Inuka today, where we will evaluate the impact of our current treatment regime on his health.
We would like to keep Inuka with us for as long as possible, but our ultimate responsibility is Inuka's welfare.
Cheng Wen-Haur (Dr)
Deputy Chief Executive Officer and Chief Life Sciences Officer
Wildlife Reserves Singapore