510 ILCS 5/9
Any dog found running at large contrary to provisions of this Act may be apprehended and impounded. For this purpose, the Administrator shall utilize any existing or available animal control facility or licensed animal shelter. The dog's owner shall pay a $25 public safety fine to be deposited into the county animal control fund or the county pet population control fund. Funds transferred to or retained by a municipality before the effective date of this amendatory Act of the 100th General Assembly under this paragraph shall continue to be transferred to and be retained by that municipality. A dog found running at large contrary to the provisions of this Act a second or subsequent time must be sterilized within 30 days after being reclaimed unless already sterilized; failure to comply shall result in impoundment.
A dog that is actively engaged in a legal hunting activity, including training, is not considered to be running at large if the dog is on land that is open to hunting or on land on which the person has obtained permission to hunt or to train a dog. A dog that is in a dog-friendly area or dog park is not considered to be running at large if the dog is monitored or supervised by a person.
510 ILCS 5/9