Hermosillo's second film was already a masterpiece in some critics' estimation, and offers insights into themes developed in later films. "Elements of social commentary on the Mexican middle class, ambiguities of gender, misogyny, and female repression are much in evidence. Structurally, the film uses assured story development, singular characterizations, and surprise endings which, in retrospect, are inevitable. The narrative revolves around the parallel lives of two couples, one older and the other young, whose lives, for all that they are different, are very much the same. Although overt depiction of gay relationships in Mexican films was not possible in 1974, the nuances of male camaraderie in The Dog's Birthday allow it to be seen today as the first gay film in the history of Mexican cinema." (UCLA Film Archive)