Processed horse head found in Natural Valley Farms' Rendering Pit on February 26, 2008. Note the absence of a captive bolt pistol hole.

There are only 2 legally approved methods for slaughtering horses in Canada - by .22 or penetrating captive bolt pistol. Both would leave a hole in the skull. What is concerning is that this horse was slaughtered and processed but it is unclear how he was killed as no hole is present.