Good afternoon,
Thank you for the message and picture. In my opinion it looks more like a fox with mange. It could be a coyote. Both animals are prevalent in Frederick County and inhabit the Brunswick area. If the animal is being a nuisance or poses a threat to pets and people, please call (301) 600-1544 to speak with an Animal Control Officer for more information. For an emergency, phone (301) 600-1603 at any time of day or night. Animal Control does not trap and remove wildlife. For information on nuisance wildlife or wildlife trapping, the Maryland Department of Natural Resources website can help.
https://dnr.maryland.gov/Wildlife/Pages/plants_wildlife/wildlifeproblems.aspx
Look for the tab wildlife, wildlife problems, if you go to their homepage. A phone number is also available. 1 (877) 463-6497