Thousands of rescued animals end up in shelters across Thailand, both government- and private-run. One is the 40ha Wildlife Friends Foundation of Thailand (WFFT) in Petchaburi province, south of Bangkok, started by Mr Edwin Wiek, a 50-year-old Dutchman who has been living in Thailand for over 25 years.
WFFT teams respond in pickup trucks to tips of animals in trouble. They rescue wildlife - from snakes and elephants to tiny, shy slow lorises - in trouble or abused for commercial gain. Some are wild species in distress as they are neglected or chained and kept in dark corners by owners.
And then there are individuals who buy animals, and after realising it was a bad decision, ask the shelter for help - like Ms Sirada Dejvuttikul. Then a quality control officer at a handicraft business in Bangkok, Ms Sirada bought a baby gibbon from Bangkok's Chatuchak market one fateful day in 1989. She named him Ooh.
And then he grew bigger, and her life changed.
An endangered species, a gibbon can weigh up to 8kg. It is a powerful ape that can swing effortlessly through the rainforest canopy.
But Ooh was confined for about four years to a small flat in Bangkok, and then for several years in an animal shelter where he was attacked by another male gibbon. Animals at rescue shelters are often psychologically traumatised and cannot socialise normally.
In 2003, Ms Sirada finally moved Ooh to WFFT, where she also got a job which enables her to be with him a lot.
Sixty and single, she sees him as family. Today he is around 25 years old - elderly for a gibbon - and has diabetes. Emotionally he is dependent on her.
Ms Sirada wept as she spoke to The Straits Times, squatting a metre away from Ooh's cage while he watched curiously, reaching out a long arm to pluck at her sleeve.
"Ooh is like my child, for whom I will be responsible for the rest of his life," she said. "Every time he was hurt I felt the pain and the sadness... If I had known what would become of this, I would not have bought him in the first place."