(a) It shall be an affirmative defense to a violation of Section 505.16(a)(1) that the dog was:
(1) Securely confined in an automobile or cage which was adequately ventilated;
(2) Being used for lawful hunting purposes;
(3) Being exhibited at a public dog show or public institution; or
(4) Engaged in any activity expressly approved by the laws of the State.
(b) It shall also be an affirmative defense to a violation of Section 505.16(a)(2) and (3) that, at the time of the occurrence, another person, domestic animal or feline was unlawfully on the property owned or exclusively controlled by the owner of such dog, and that such dog was not unsecured.
(c) No public law enforcement agency or member thereof shall be convicted of a violation of Section 505.16 where the dog is owned by the agency and being utilized for law enforcement purposes.