Bloodhound can pick up a days old human scent at a long distance. German Shepherds are one of the most common breeds employed in scent detection work and are praised for their keen sense of smell, focus, and determination. German Shepherds are also used in search and rescue efforts not just for cadaver. A bit of info on cadaver dogs - Cadaver dogs are able to tell the difference between human remains and animal remains, which means they’ll know right away if the scent they’re picking up is from a person or from decomposing wildlife - they're trained to differentiate between types of decomposing flesh. Because they’re trained to pick up scents both on the ground and in the air, cadaver dogs can identify crime scenes even if the body has since been moved. Depending on the circumstances, they may also be able to lead search teams to where the body was relocated to. They can identify hundreds of different scents related to decomposition.