Decades of analyses indicate that dog (Canis lupus familiaris L) and human (Homo sapiens L) archaeological bone collagen δ13C and δ15N isotopic ratios are often similar, which presumably indicates similar diets. This makes sense given that most dogs occupy human-created environments and that much if not all of their food is sourced from human behavior. This has led some to suggest that dog isotopic ratios can be used as proxies for human ratios in archaeological contexts where human bone is not available for analysis. A meta-analysis of 64 cases with dog and human bone collagen δ13C and δ15N isotopic ratios indicates dog isotope ratios are not good direct proxies for humans when considering human diets. However, dog ratios can be used cautiously when considering specific food sources, such as C4-pathway grain crops, recognizing the possibility of false negatives in the absence of other subsistence evidence.