Fatty's Faithful Fido (1915)
Two men like the same woman, and she prefers the large, strong one over the smaller, nimble dandy. The rivalry first comes to a head when she rejects the dandy in front of a Chinese laundry; a fight ensues, and the big guy's dog adds to the dandy's humiliation. Then, that night, during a dance held at the neighborhood fitness center, the dandy hires some thugs to beat up his rival. The plan goes awry, which precipitates chaos. Fido's on hand to add to the confusion.