In the early spring of 1909, the city was dealing with a rabies scare. Loose dogs running about town had been an on-again, off-again problem for years, and loose animals in general were an issue addressed by city ordinances dating back to the city's earliest days. Eventually the rabies alert would culminate in at least one dog being shot dead on the street in town. Prior to that, the March 1, 1909 Ypsilanti Daily Press offered the salutary tale of a dog who was doing things right, the tale of Denny.
Do you know Denny?
Denny is the homeliest, orneriest dog in seven counties. He is a full-blooded yellow cur with no particular claim to distinction except that he is without doubt the homeliest dog in the world today.
But Denny is a politician, undoubtedly, for he has appeared on the street wearing a neat and reassuring muzzle although no proclamation has been issued by the mayor anent the recent case of rabies. Denny's one desire seems to be to reassure the citizens whom he may meet that he is not liable to a similar attack and in this way to provide for the safety of the children.
Denny is credited with hunting up the muzzle and putting it on himself, but this statement is not vouched for.
--March 1, 1909 Ypsilanti Daily Press