The domestication of the dog is a complex and unresolved topic. But at this point I am convinced that this is one domestication event which well predates agriculture. To some extent this is common sense. There are tentative archaeological finds of domestic dogs in the New World almost immediately after widespread human habitation of the Western hemisphere, >10,000 years ago. More concretely domestic dog DNA has been retrieved from ~9,250 year old coprolites in Texas. The distinctiveness of the New World dogs is well attested genetically. Eskimo dogs for example are nested in a well diverged clade with “ancient dogs” (e.g., Basenji), indicating their early separation from the main Eurasian stock. Additionally, from talking to a dog geneticist I am to understand that the Eskimo dogs themselves are likely new arrivals, and superseded older dog lineages in the far north.
These results suggest to me that by the late Pleistocene many of the hunter-gatherer populations of Eurasia existed in a symbiotic relationship with domestic dogs. I suspect that the dog lineages in fact predate the late Pleistocene, and the earliest tendencies toward coexistence with humans may date to before the Last Glacial Maximum. And yet an interesting sidelight …