The Frenchwoman who underwent the world's first face transplant this week sustained her original injuries when her labrador tried to rouse her from a pill-induced sleep, it emerged yesterday.

Isabelle Dinoire, 38, whose nose, lips and chin were replaced in 15 hours of surgery on Sunday, has recovered sufficiently to be able to eat small mouthfuls and drink fruit juice, her doctors said yesterday.

Her first instinct on recovering consciousness 24 hours after the pioneering operation was to thank her doctors. "Her first word was 'merci'," said Bernard Devauchelle, one of the surgeons who carried out the operation at Amiens, northern France.

But according to one of her teenage daughters, it may be the family dog - which has since been destroyed - that deserves the thanks. "She had taken pills, she was unconscious," the daughter said of the incident that led to her mother's injuries six months ago.

"When the dog realised that it tried to wake her. After that we don't know what happened with the dog, whether it bit or clawed her, but it managed to pull her awake," she said. "In a way, it was lucky for her that the dog was there."

Leading transplant surgeon Jean-Michael Dubernard dismissed suggestions that the pills episode had been a suicide attempt.

The divorced mother-of-two was mauled by her labrador at her home in Valenciennes in May, leaving her with facial injuries which her doctors said made it difficult for her to speak and eat.

Prof Dubernard acknowledged that he had initial reservations about the procedure. But he added that when he saw the extent of the woman's disfigurement, "I no longer hesitated for a second".

The grafted material came from a brain-dead donor. Such an operation has not been attempted before and doctors say there are still risks of complications, including rejection of the tissue and an increased danger of cancer because of the drugs used to prevent rejection.

Prof Dubernard admitted there were "many, many ethical problems" surrounding the intervention, but the injuries would have been virtually impossible to repair with conventional surgery.