To be all honest I don't believe that Dumor is made by Purina anymore.It doesn't matter. Purina/Dumor are both owned by Land O' Lakes. Dumor was recalled less than 2 years ago: http://www.fda.gov/Safety/Recalls/ucm313507.htm
I wouldn't use them, nor recommend them.
I believe the last recall Cargill had it included Nutrena, Dumor, Producers Pride, and Showmaster.
Also if your going to "boycott" Land-O-Lake feeds even if there not on the recall list then you better lengthen that list you have a whole lot more and to include the organic feeds that Purina makes along with Nutrena feeds since Cargill makes Nuterena and is also affiliated with Land-O-Lake.