From what I researched so far, it is still unknown exactly when dogs were domesticated. It is between 45,000 B.C. - 15,000 B.C.. I want to be accurate when I develop my characters, especially for the hunter-gatherer human. 

 http://en.wikipedia.org/wiki/Origin_of_the_domestic_dog

 http://www.timemaps.com/hunter-gatherer

 http://www.the-scientist.com/?articles.view/articleNo/38279/title/Origin-of-Domestic-Dogs/

 http://www.scientificamerican.com/article/the-origin-of-dogs/

 http://news.nationalgeographic.com/news/2013/13/131114-europe-dog-domestication-wolves-hunter-gatherers/?rptregcta=reg_free_np&rptregcampaign=20131016_rw_membership_r1p_us_se_w#

 http://news.nationalgeographic.com/news/2013/03/130302-dog-domestic-evolution-science-wolf-wolves-human/#

 http://sciencenordic.com/dna-reveals-new-picture-dog-origins

 http://www.doglistener.co.uk/choosing/origin_dogs.shtml

 http://newguinea-singing-dog-conservation.org/Tidbits/OriginOfTheDog.pdf