When livestock are killed by predators, circumstantial evidence is often the only information available to determine which predator species made the kill. Evidence can consist of rake marks, scat, hair, attack points, tracks, sightings, and canine punctures. Canine punctures in particular can be informative because they offer the most direct evidence of attack, particularly if they are linked to tissue hemorrhaging. When investigating canine punctures, a common technique to identify the predator species is to measure the canine cusp spread for maxillary and mandibular tips as measured from the maxillary to maxillary tip or mandibular to mandibular tip. The assumption is that different predator species will have different and distinct canine spread. Surprisingly, little has been published on canine spread and comparing different carnivore species, leaving wildlife managers unable to reliably use this technique for predator identification. During 2008, we started a project to assess the width of canine spread in carnivores. The majority of information gathered to date shows a narrow range of measurements for coyotes and broad variation in feral/free ranging dogs that can overlap coyote measurements. The information provided on scientifically measured canine spread will assist the wildlife damage manager in determining the actual predatory species, especially when used with additional evidence gathered on site.