SINGAPORE - Both the owner and his pets have had abusive pasts.
He struggled with anger management issues, was involved in fights and secret societies.
The dogs he cares for now used to be malnourished and were kept in overcrowded cages by previous owners.
Today, man and animals are trying to deal with unhappy histories so that they can bring joy to others through pet therapy.
Mr Derrick Tan, 33, is head of operations at Sunny Height, a pet daycare centre.
Last Thursday, 19 seniors aged 60 to 81 from the Geylang East Home for the Aged, Social Day Centre, went there to cuddle 20 dogs.
The idea is that petting these animals would benefit the elderly emotionally and socially. It's their third time returning for this pet therapy session as the seniors have given feedback that they enjoy these sessions.
Mr Tan is also president of Voices for Animals (VFA), a rehabilitation society for ex-breeding dogs and cats.
It provides pet therapy sessions and have worked with the elderly and people with special needs.
Mr Tan said: "We believe in the healing powers of love. We try to help mostly those animals that are waiting for their time to go, for those that are helpless, those that people don't really pay attention to.
"I strongly believe in pet therapy. There's something about loving an animal and the way it loves you back unconditionally. It calms you down and it heals both ways."
They have saved about 80 dogs and cats from puppy mills and breeders. Some were rescued off the streets.
He said many were severely underfed, some had bad skin diseases, heartworms, and some had renal and liver failure.
Charismatic with both the animals and the elderly, it's hard to imagine that Mr Tan was once a self-professed 'Ah Beng'.
The heavily-tattooed man admitted to The New Paper that when he was 14, he was involved with secret societies.
But all that has changed and now, together with the animals VFA saves, Mr Tan plans to give back to society, one cuddle at a time.
Ex-boxer Michael Loh, 79, told TNP while a white dog sat on his lap: "I used to have a dog just like this named Baby and I loved her very much. Dogs are very smart and intelligent creatures."
Since the previous pet therapy session, Madam Soh Yin Leng, 75, felt so comfortable with the dogs that she even wanted to swim with them at the ground's swimming pool for dogs.
She said: "I told everyone I would bring my bathing suit this time round so I can swim with the dogs and play with them more."