Pseudopregnancy is a common phenomenon that occurs in the intact, non-pregnant female dog during the diestrus or anestrus period of her estrous cycle. Pseudo-pregnancy may be characterized by swelling of the mammary glands, swelling of the abdomen, milk production and a change in the female's behavior such as mothering of objects or other animals, restlessness , aggression, nesting and anorexia (Hermo, 631). For the subordinate gray wolf, this phenomenon is a typical behavior to care for the young while the alpha female, and the only female to mate and give birth to the cubs, is in search of food for the pack. This process evolved due to the fact that the gray wolf is a very social animal with a monogamous alpha male and female who will be the only sexual pair in the pack to produce offspring; they are also the pack leaders who lead all hunting expeditions (ASA, 251-259). The domestic dog that the majority of citizens living in the United States of America now have as a pet and that many people consider part of the family is a descendant of the wolf. Although there are many dog ​​breeds in the world, they all share the wolf as a common ancestor, but they lead a very different lifestyle than their ancestors (Ehresman, 1). What kinds of effects might their common pseudo-pregnancy phenomenon have on the dogs we all know and love who experience this syndrome without needing to care for any pup? Domestic dogs are not like gray wolves in many ways. A major difference between domestic dogs that live as pets and wolves that live in packs is that the dogs do not eat a restricted diet like their distant relative, the wolf. Wolves do not always have enough food and are forced... middle of paper ......rus, Pregnancy and pseudo-pregnancy in the Labrador female dog. " Theriogenology 27.6 (1987): 827-40. UW Libraries Proxy Service Research Division, Department of Obstetrics and Gynecology, Bethesda University of Health Sciences, MD, June 1987. Web, November 5, 2013. Ehresman, Dan “Gray Wolf.” Environmental Center, February-March 2012. Web. November 5, 2013. Hermo, G., PG Gerez, AM Dragonetti and C. Gobello. “Effect of short-term restricted food intake on canine reproduction.” Animals 44.4 (2009): 631-33. Web November 5, 2013. Tsutsui, T., N. Kirihara, T. Hori, and PW Concannon. “Plasma progesterone and prolactin concentrations in obviously pseudo-pregnant dogs. a clinical study." Theriogenology 67.5 (2007): 1032-038. UW Libraries Proxy Service. March 15, 2007. Web. November 6.. 2013.