In the palliative care centre at Calais Hospital in northern France, Marion, 24, who has metastatic cancer, cuddles her seven-year-old son, Ethan, as Peyo nuzzles them both. ‘With Peyo, we try to recreate life at the end of life, in order to fight, and create an energy to accompany families and caregivers,’ says his trainer, Hassen Bouchakour. Peyo and Bouchakour work with Les Sabots du Coeur, an organisation devoted to therapy, and with scientists who are studying Peyo’s ability to reduce patients’ anxiety and comfort people in pain

At the hospital Peyo tells his trainer which room he wants to enter next by stopping or raising his leg. Peyo is 15 and seems able to detect when humans have cancers and tumours. He stayed nearly two hours here, watching over a dying woman. ‘I accompany him but I let him do what he wants, he’s the one who decides,’ says Bouchakour. ‘What really pushed scientists to take an interest in him and open the health establishment doors to us, was this [seeming] ability to greatly reduce [the patients’ dosage of] all hard drugs and thus allow a more peaceful departure,’ he says

Hassen Bouchakour prepares Peyo for a new day at Calais Hospital. ‘Peyo’s nickname given by the medical team name is Doctor Peyo,’ says the trainer. For a long time the pair were known for taking part in equestrian shows. But Peyo was constantly looking for human contact. After shows, he would pick out people in the crowd, approach them and choose to stay next to them. Bouchakour began to suspect Peyo was choosing people who were weakened morally, physically or psychologically. After four years of investigation, veterinary specialists believe Peyo’s brain functions in a unique way

In Calais Hospital, Marion pats Peyo while the medical team help her with her pain relief for metastatic cancer. Peyo and Bouchakour are her allies, she says, and they come to see her almost every day. ‘Hassen and Peyo are part of the team, they are not only good for the patients but for us too. When it is hard, we are happy to know they are here,’ says Anne Sophie, a nurse at the palliative care centre

Outside in the car park of Calais Hospital, it is the end of the working day for Hassen Bouchakour and ‘Doctor Peyo’. ‘Since 2016, we have supported around 1,000 people until their last breath in the various services in which we operate. Peyo is my other half, he is my life partner, he is everything to me,’ says Bouchakour

Isaac, nine, is proud to show off his new friend, Peyo, to his mother who is just coming out of surgery. ‘Isaac has associated the hospital with Peyo. Today, if he is happy to come to the hospital to see his mother, it is thanks to this horse,’ says his father, Thomas

Peyo licks the hands of 64-year-old Roger who has just returned for the day to the palliative care unit for a blood transfusion. Roger is happy to see his ‘favourite doctor’ again. ‘Tonight he’s going to sleep well [because] he saw Peyo. As soon as he sees him he sleeps like a baby,’ says his wife

In the parking garage at Calais Hospital, Peyo and Bouchakour accompany Roger to the ambulance that will take him home after his treatment. Specialists are still trying to find out more about Peyo’s apparently instinctive ability to comfort those who are sick

Peyo guards the door of a patient while Bouchakour talks to the medical team. ‘Hassen and Peyo don’t only provide comfort to patients but to us, too. In tough situations we are very happy to see them around,’ says said Nathalie, a nurse at palliative care centre

Bouchakour is always very careful with hygiene and Peyo is washed and disinfected before and after hospital visits. It takes two hours to get the horse ready. ‘When I clean him with disinfectant wipes it is to protect him,’ says Bouchakour. ‘Luckily, he likes it.’ Peyo has learned to indicate when he needs to go outside by moving his body from right to left. • This caption was amended on 15 March 2021 to remove a quote which incorrectly indicated that no transmissible disease is passed from horses to humans.

Peyo and Hassen visit their friend Robert, a former horse rider who has terminal cancer and who is receiving pain relief in hospital

The legs of Peyo, Bouchakour and Robert, the patient they are visiting. ‘I am to some extent this horse’s collateral damage, I didn’t ask for this. It took me a while to accept it. It put an end to my successful career as a sportsman, and as a showman. It was very complicated to no longer be the master, and to be forced to admit that when [Peyo] detects someone [is sick], I am no longer in control. When he decides, I cannot hold him back, it’s a need, it’s visceral, it is in him, he needs to go and cling onto the specific person he has chosen,’ says Bouchakour

Peyo stands guard at the door of Robert’s room. Scientists and doctors are still puzzled by some of the horse’s behaviour, such as here when he adopts a menacing pose to bar anyone from entering the room

Peyo is happy to see his old friend, Daniel, 67, a former equestrian, who has terminal cancer. ‘At home, as soon as we speak to Dad about Peyo, he cries, he has stars in his eyes,’ says his son Gerald

Daniel died in January. At the request of the family, Bouchakour and Peyo accompanied his coffin at the funeral

Peyo and Hassen say their last goodbye to Daniel, who died of cancer

Bouchakour and Peyo enjoy time off on the beach in Calais, after a hard day at the hospital. ‘In the past, people died at home. Today, it is so hard because people are often dying in isolation and we see death as a drama,’ says Bouchakour. ‘It is a unique experience to look after a person who is facing death, to stay with them and tell them: “Don’t worry, you can go in peace, you won’t be forgotten”.’