The retraction of a paper from a prestigious veterinary journal for the first time in its 147-year history is stoking discussion about the reliability of research conducted by large corporations — and whether some dog food contains unsafe levels of copper.

The paper, entitled "Sixteen years of canine hepatic copper concentrations within normal reference ranges in dogs fed a broad range of commercial diets," was published online on March 7 in the Journal of the American Veterinary Medical Association (JAVMA). It was retracted on May 21.

The paper's authors voluntarily requested the retraction after being made aware by the journal that it had received a number of letters to the editor from veterinarians maintaining the paper has major flaws. In their retraction notice, the paper's authors said they subsequently discovered new data that had inadvertently been left out of their analysis. 

The paper's publication and subsequent retraction come as pet food companies face increased scrutiny from some veterinary internal medicine specialists who have been contending for years that high copper levels in some commercial dog foods are sickening pets. The veterinarians have been unable to convince authorities in the United States to impose a maximum copper limit in dog food, or even establish a voluntary copper-reporting framework.

Source: https://news.vin.com/default.aspx?pid=210&catId=614&Id=12166383