Penka wandered away from her herd near the Bulgarian village of Mazarachevo last month and walked out of the bloc into neighboring Serbia.
When she was returned two weeks later, authorities said she would have to be put down as she had violated guidelines under which animals entering the European Union have to have papers verifying their health, Presstv reported.
Penka’s plight prompted protests on social media, particularly in Britain where eurosceptic campaigners and publications held her up as a victim of Brussels bureaucracy.
Animal rights campaigners, including former Beatle Sir Paul McCartney, signed petitions asking Bulgaria to save the five-year-old animal.
The Bulgarian Food Safety Agency agreed to review the case and said on Monday that lab tests had given her a clean bill of health. “It is expected the animal will be allowed back to her former home in the village of Mazarachevo by the end of the week,” the agency said in a statement.