"There were two rescues interested in this dog and the shelter manager overrode those notes and said to have her killed by the end of the day," Melissa Farley Law of Petaluma Pet Pals told KPIX.
Another dog, named Tommy, was also put down around the same time. That euthanasia is also under investigation.
"In terms of what we are doing, we have opened an official investigation and are currently investigating the circumstances that led to this error, as well as examining our departmental processes to ensure that such errors do not happen again," Ward said in a statement to The Mercury News. "We urge your patience as we conduct our investigation. While we cannot undo this terrible mistake, we will learn from it and improve our efforts to save as many lives as possible."
County officials hope to have the investigations completed by the end of the week.