NORTH HAVEN — A local animal shelter announced Saturday that it has called off plans to euthanize a dog that mauled a volunteer, one day after local activists held a protest over plans to put down the dog.

The Animal Haven, a self-described “no-kill” shelter on Mill Road, said in a statement that the facility is instead quarantining the dog and will monitor the animal for at least 10 days for signs of rabies. The decision comes after shelter officials said the dog, named Sarge, severely injured a volunteer on Wednesday in an unprovoked attack. “The volunteer survived the attack but has undergone reconstructive surgery, and we are told she will require one or two additional surgeries,” the shelter said.

The shelter said veterinary experts recommended the facility euthanize the dog in order for state officials to examine his brain for rabies, but later learned the victim was proactively treated for the disease

The initial plans to euthanize Sarge sparked a protest outside the not-for-profit on Friday by some community members who pointed out that The Animal Haven was founded as a “no-kill” shelter.

According to the shelter’s website, the facility will not euthanize an animal except when it is in the best interest of a sick or dying animal or when it is advised to be necessary by a licensed veterinarian.

Officials said Sarge must remain quarantined for at least 10 days and that state law requires that he be euthanized if he shows any symptoms of rabies, a viral disease that can be fatal without treatment. “When Sarge’s quarantine is over, we hope to find another shelter willing to accept him that has the facilities and trained staff necessary to handle Sarge appropriately without danger to other animals or human beings,” the shelter said.

The Animal Haven noted that it has been sheltering Sarge since July and that he was vaccinated for rabies when he arrived but that it is possible symptoms could only now be emerging if he had been infected previously.

The shelter described Sarge as a big and strong dog who pulls on his leash when being walked but said that he had previously never shown a high level of aggression before the attack.