MADRID — A dog named Excalibur who belonged to an Ebola-infected nurse was destroyed on Wednesday, even as protesters and animal rights activists surrounded the Madrid home of the nurse and her husband. An online petition calling for the dog’s life to be spared had drawn hundreds of thousands of signatures.

The furor came amid questions about whether dogs can get and transmit the disease.

In the United States, a spokesman for the federal Centers for Disease Control and Prevention, Thomas Skinner, said Wednesday that studies had shown that dogs can have an immune response to Ebola, meaning that they can become infected. But he said there had been no reports of dogs or cats developing Ebola symptoms or passing the disease to other animals or to people.

The death of Excalibur, a 12-year-old rescue dog, was confirmed to reporters by Javier Rodríguez, an official from Madrid’s regional government. The body is expected to be cremated.