D.C. Code § 1-303.41: Regulations for the keeping, leashing, and running at large of dogs.

The Council of the District of Columbia is hereby authorized and empowered to make and modify, and the Mayor of the District of Columbia is hereby authorized and empowered to enforce, regulations in and for the District of Columbia to regulate the keeping and leashing of dogs and to regulate or prohibit the running at large of dogs, including penalties for violations of such regulations as provided in § 1-303.05.