According to Arizona State Museum, "the most common human bones to be mistaken for animal bones are the bones of infants." The adult human body houses 206 bones while the dog's body generally has 319. There are various points at which you can tell the difference.
Humans have larger brains and smaller facial features than those of dogs. The skull is larger to hold the brain and does not protrude out as it does for the canine nose. The human skull sits vertical while the dog's skull sits horizontal.
Canines typically have 42 teeth. Humans on the other hand have 32. The biggest difference is that canine teeth are much sharper, designed for ripping and tearing.
The arms of a human are less robust than the canine's forelimbs. The two bones of the human forearm are separate, but the two bones of the dog's forelimbs are often fused together.
A dog's spine lacks the curve shown in human spines. The canine pelvis is long and narrow while the human pelvis is short and broad. In humans the femur is the longest bone in the body, but for dogs, the femur is similar in length to other limb bones.
There is greater density in canine bones than in human bones. Comparatively, the dog's forelimb and rear limb are a quarter of the total diameter thicker than the human upper arm and thigh. Canine bones are also less porous.