The shots were fired near Lawndale Avenue and Division Street in the city's Humboldt Park neighborhood, according to Chicago police.
During a street stop, Chicago police officers said an "aggressive" dog tried to bite on of the officers.
In response, the officer fired his weapon once, and shot the dog.
Chicago police did not provide any more information on the incident. The condition of the dog is unknown.
CPD said no officers were injured. Chicago police are investigating the incident.