In this study from 2010 (and in others similar, some of which are referenced in the works cited at the end of the article), "dogs, like infants but unlike wolves, make perseverative search errors that can be explained by the use of ostensive cues from the experimenter." In other words, dogs read human faces.
Also, there is a similar study about dogs reading the right side of face (the more emotionally expressive) here:
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