A 16-year-old lion named Chaos reportedly did not live up to his name when he was brought in for his skin cancer treatment at De Muelenaere Oncology practice in Arcadia, Pretoria in South Africa.

Radiation oncologist Dr Ingo De Mûelenaere, who has experience in prostate brachytherapy, intensity-modulated radiation therapy and stereotactic radiosurgery, performed the treatment.

Chaos underwent his first radiation session at Muelmed Radiation Oncology on Tuesday morning.

De Mûelenaere was one of the five radiation therapists who treated Chaos for skin cancer on his nose, in a session which lasted about five minutes.

Chaos is one of the many animals the oncology practice has treated.

The practice halls and wards have welcomed domestic animals, and even a leopard, as well as a cheetah which came in for various treatments.

Oncologist Dr Marlene Soares said most of the animals were brought in by their vets.

Soares said the radiation treatment was one of the four treatments the wild cat had to undergo.

The machine used to treat the skin cancer is called the Linac, which is also used to treat humans.

However, because Chaos weighed more than 260kg he was treated while he lay on a stretcher.

“When we were done, he was awake and grumpy but he did not live up to his name,” she added.

Kara Heynis of Lory Park Zoo in Midrand, near Joburg, said Chaos had lived his whole life at the zoo and they were “very happy” he was doing well, and were hopeful that the treatment would help.

“He is now in his cage and not causing Chaos, as his name suggests,” she said yesterday.

Heynis said the lion would again be taken for treatment on Wednesday, and concluded after four sessions.