510 ILCS 5/26

(a) Except as otherwise provided in this Act, any person violating or aiding in or abetting the violation of any provision of this Act, or counterfeiting or forging any certificate, permit, or tag, or making any misrepresentation in regard to any matter prescribed by this Act, or resisting, obstructing, or impeding the Administrator or any authorized officer in enforcing this Act, or refusing to produce for inoculation any dog in his possession, or who removes a tag from a dog for purposes of destroying or concealing its identity, is guilty of a Class C misdemeanor for a first offense and for a subsequent offense, is guilty of a Class B misdemeanor.
Each day a person fails to comply constitutes a separate offense. Each State's Attorney to whom the Administrator reports any violation of this Act shall cause appropriate proceedings to be instituted in the proper courts without delay and to be prosecuted in the manner provided by law.
(b) If the owner of a vicious dog subject to enclosure:
1. (1) fails to maintain or keep the dog in an enclosure or fails to spay or neuter the dog within the time period prescribed; and
2. (2) the dog inflicts serious physical injury upon any other person or causes the death of another person; and
3. (3) the attack is unprovoked in a place where such person is peaceably conducting himself or herself and where such person may lawfully be; the owner shall be guilty of a Class 3 felony, unless the owner knowingly allowed the dog to run at large or failed to take steps to keep the dog in an enclosure then the owner shall be guilty of a Class 2 felony. The penalty provided in this paragraph shall be in addition to any other criminal or civil sanction provided by law.
(c) If the owner of a dangerous dog knowingly fails to comply with any order regarding the dog and the dog inflicts serious physical injury on a person or a companion animal, the owner shall be guilty of a Class 4 felony. If the owner of a dangerous dog knowingly fails to comply with any order regarding the dog and the dog kills a person the owner shall be guilty of a Class 3 felony.

(from Ch. 8, par. 376)

(Source: P.A. 93-548, eff. 8-19-03; 94-639, eff. 8-22-05; 94-819, eff. 5-31-06.)