Spanish authorities have been criticised after the nurse contracted Ebola in the country’s best-equipped quarantine unit
Activists scuffled with police outside her home as the dog was taken away.
The nurse, Teresa Romero, is the first person known to have contracted the deadly virus outside West Africa.
She had treated two missionaries who later died from Ebola. The virus has killed 3,879 people, mostly in Liberia, Sierra Leone and Guinea.
A court order to euthanise Ms Romero’s dog was issued on Tuesday despite uncertainty over whether the animal was also infected or risked spreading the disease.
On Wednesday about 50 animal rights activists held a protest outside the nurse’s home in Madrid, shouting “assassins”.
Two protesters were hurt when they tried to stop the van in which the animal was being transported, El Pais newspaper reported.
The fate of the dog, named Excalibur, sparked huge interest on social networks, after Ms Romero’s husband, who like her is being kept in isolation in a hospital, alerted animal protection groups via social networks.
Ms Romero, 40, was part of a team of about 30 staff at the Carlos III hospital in Madrid looking after Spanish missionaries after they were repatriated from West Africa.
She told the El Pais newspaper that she might have become infected when removing her protective suit after cleaning one of the missionaries’ room.
Clued from BBC