Be aware that dogs with unknown histories might come with illnesses, so you may spend a bit extra on veterinary care at first if you adopt from a «questionable» shelter. (thesprucepets.com)
Please please please do not advise people to buy used seats with unknown history because it can be deadly in the event of a crash. (topbabyspot.com)
It is our usual policy not to adopt dogs with unknown histories to a home with young children under 5 years of age. (bostonterrierrescuecanada.com)