JOHANNESBURG - A rhino in South Africa that survived an attack by poachers who cut off her horns, leaving a massive wound on her face, has had a setback in her medical treatment. However, conservationists said Friday that the rhino is starting to heal.

The rhino damaged a protective mask by rubbing her face against enclosure walls, forcing veterinarians to remove the mask, according to a conservation group, Saving the Survivors. It had been placed on the 4-year-old rhino's face in a May 18 surgery in Eastern Cape province.

Poachers had darted the rhino with a tranquilizer and severed her horns while she was sedated. The rhino's rescuers named her Hope.

In a statement, veterinarian Dr. William Fowlds said Hope's face shield must be left off for now, despite concerns about infection. But he said tissue formation and improved blood flow to the wound area indicate that healing has begun.

Hope was given more antibiotics and medicine to ward off fly larvae and maggots, according to Fowlds. He said the rhino has “a long, long road” of recovery ahead.

Saving the Survivors, which treats rhinos with gunshot wounds, facial gouges and other injuries inflicted by poachers, said it has received comments and inquiries about Hope's case from around the world.

Poachers killed more than 1,200 rhinos last year in South Africa, home to most of the world's rhinos. Demand for rhino horn is high in parts of Asia where it is seen as a status symbol and a cure for illness despite a lack of evidence that it can heal. The horn is made of keratin, a substance also found in human fingernails.