Replacement Caster

Rob Veteran
I have a set of the dolly's that I am very happy with. I have benn using them for about 5 seasons now. Last time I rolled the plow into my garage, one of the casters slipped into a gap between the driveway and the garage and got bent. Not too bad, but enough so that the wheel will drag and makes the unit a little uneven and difficult to roll. Can I purchase a replacment caster ?