(CNN) — Elephants may be known for their size and strength, but tourists who ride on their backs can still do great harm, as this photo shared by a wildlife rescue group in Thailand shows.

The picture provided by the Wildlife Friends Foundation in Thailand (WFFT) depicts Pai Lin, a 71-year-old female whose spine has become disfigured after 25 years of working in the tourism industry, where she was forced to carry up to six tourists at a time.

“Pai Lin’s back still bears scars from old pressure points,” the group said. “This continuous pressure on (elephants’) bodies can deteriorate the tissue and bones on their back, causing irreversible physical damage to their spines.”

Elephant rides are a popular tourist activity in countries across Southeast Asia, but activists say the practice is a form of animal cruelty as their bodies are not designed to be ridden. They say the animals are also often abused and exploited in other industries like trekking and logging, with many dying from exhaustion and malnutrition as they are literally worked to death.

“Pai Lin arrived at our sanctuary in 2006 after working in the Thai tourism industry,” Edwin Wiek, director and founder of the WFFT, told CNN.

“She was given up by her previous owner who felt that she was too slow and always in pain and couldn’t work well anymore,” he added.

Tom Taylor, the group’s project director, added that elephants’ backs were not designed to carry heavy weight.

“Their spines extend upwards,” Taylor said. “Constant pressure on their backbones from tourists can result in permanent physical damage — which can be seen in Pai Lin.”

Wiek said the group was sharing Pai Lin’s story to raise awareness about elephant cruelty and remind people never to ride them, as tourism returned to the country following the pandemic.

“It’s important to understand that elephants, unlike horses, are not bred to be ridden. They are not domesticated animals and are taken from the wild and kept in awful conditions,” he said.

Pai Lin is living out her days with 24 other rescued elephants in WFFT’s sanctuary near the seaside town of Hua Hin, about a 2.5-hour drive from Bangkok.

She’s older now and has put on weight. “She’s fatter than when she first came to us,” Wiek said. “But you can see the shape of her spine very clearly — it’s a physical deformity she will have to live with, but she’s doing well.”

The introverted “old lady” enjoys having her own space.

“She’s definitely an introvert and doesn’t really enjoy being around the company of other elephants but likes attention from people,” Wiek added.

“She does get moody when it involves food but she is a very lovely elephant.”

This is what years of tourist rides do to an elephant