Iowa State University Veterinarian Records, RS 22/6/0/9, University Archives, Special Collections Department, Iowa State University, http://www.add.lib.iastate.edu/spcl/arch/rgrp/22-6-0-9.html
On October 3, 1986, Alpo Petfoods, Inc., filed suit in U.S. District Court against Ralston Purina, the largest pet food manufacturer in the United States. Alpo claims Purina falsely advertised its reformulated Purina Puppy Chow. Since October 1985, Purina has been advenising in major veterinary journals and other publications that Puppy Chow reduces the incidence of canine hip dysplasia (CHD)I. Canine hip dysplasia is believed to be of multifactorial origin. The disease primarily affects large breeds of dog, such as the German Shepherd and St. Bernard, and is known to have a polygenic inherited component. Whether or not nutrition can be a factor in the prevention and occurrence of CHD is the basis ofthe dispute between Alpo and Purina.
Berge, Kathleen W.
"Controversy over Nutrition and Hip Dysplasia,"
Iowa State University Veterinarian: Vol. 49
, Article 13.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol49/iss1/13