Dog Day was originally distributed in France as Canicule. In one of his last film appearances, Lee Marvin portrays a gunman on the lam with girlfriend Tina Louise. He briefly takes refuge with a farm family whose idiotic excesses make Marvin's former criminal associates seem like choirboys. The wife of the household (Miou-Miou) falls in love with Marvin, to the extent of planning his escape when the law catches up with him. Also craving Marvin's sexual attentions is the wife's sister-in-law (Bernadette Lafont), the craziest and most pathetic of the bunch. Dog Day was based on Herman, a novel by Jean Vautrin.
~ Hal Erickson, All Movie Guide