Probably not in Petsmart itself but petsmarts do have local rescues they work with, who I know most need additional help.
You can absolutely get volunteer hours with the adoption charities that set up on weekends. There are a couple dog charities and at least one cat charity on Saturdays. My daughter volunteers for one of the dog charities and has for years.
No I worked their until A months ago. And they don't do that there
Thanks! Your answer is awaiting moderation.