From Section 10-416(b) of the MD Annotated Code:
(b)(1) Except as provided in regulations adopted by the Department under paragraph (2) of this subsection, a person may not:
(i) Take a dog into the woods or possess or control a dog in the woods; and
(ii) Use the dog to hunt or pursue deer.
(2) The Department shall adopt regulations governing the use of dogs to aid in the prompt recovery of killed, wounded, or injured deer.
(3) (i) In Baltimore, Harford, Howard, Montgomery, Prince George's, Somerset, and Worcester counties, a person may not kill a dog found pursuing a deer.
(ii) In all other counties, any Natural Resources police officer, law enforcement officer,
or any other person may kill any dog found pursuing any deer, except in accordance with regulations adopted under paragraph (2) of this subsection.
(iii) In Caroline, Dorchester, Talbot, Kent, Anne Arundel, Cecil, Charles, Garrett, St. Mary's, Queen Anne's, Frederick, Carroll, and Calvert counties, dogs that are engaged in fox hunting and who have broken away may not be killed under this paragraph.
http://law.justia.com/codes/maryland/2005/gnr/10-416.html