Here's a link to laws state by state.
https://www.animallaw.info/topic/tab...arked-vehicles Below applies to Maryland:
Transportation. Title 21. Vehicle Laws--Rules of the Road. Subtitle 10. Stopping, Standing, and Parking.
§ 21-1004.1. Domestic animals left in vehicle
(a) A person may not leave a cat or dog unattended in a standing or parked motor vehicle in a manner that endangers the health or safety of the cat or dog.
(b) Except as provided in subsection (c) of this section, a person may use reasonable force to remove from a motor vehicle a cat or dog left in the vehicle in violation of the provisions of subsection (a) of this section if the person is:
(1) A law enforcement officer;
(2) A public safety employee of the State or of a local governing body;
(3) An animal control officer under the jurisdiction of the State or a local governing body;
(4) An officer of a society or association, incorporated under the laws of this State for the prevention of cruelty to animals, authorized to make arrests under the provisions of § 10-609 of the Criminal Law Article; or
(5) A volunteer or professional of a fire and rescue service.
(c) A person may not use force of any kind to remove from a motor vehicle:
(1) A dog used by the State or a local governing body for police work while the dog is on duty; or
(2) A cat or dog in the custody of an animal control officer.
(d) A person described in subsection (b) of this section may not be held liable for any damages directly resulting from actions taken under the provisions of subsection (b) of this section.
CREDIT(S)
Acts 1987, c. 611; Acts 1988, c. 296. Amended by Acts 2002, c. 213, § 6, eff. Oct. 1, 2002.