The legal definition of "No Kill" means that the facility does not euthanize for space. Period. "No Kill" facilities can and do euthanize animals. If the animal gets too sick or injured to affordably treat or becomes too unstable/aggressive to be adopted without liability, they can legally euthanize, without jeopardizing their "No Kill" status. "No Kill" shelters can and do refuse people who show up with animals they deem unadoptable. "No Kill" shelters can and do refuse to take back animals they have adopted out. So, where do these people go with their animals when "No Kill" facilities refuse them? To an "Open Door" shelter. It does not matter whether you throw your support behind a "No Kill" or "Open Door" shelter. Just know that euthansia does occur at both.