a. Any animal shall be deemed to be under reasonable control when such a animal is on the premises of its owner or custodian of such animal, premises being construed not to include the parkway and sidewalk in front of the owner's or custodian's premises. An animal at large shall be deemed to be not under reasonable control.
b. An animal shall be deemed not to be under reasonable control when such an animal commits damage to the person or property of anyone other than the owner or custodian, except in defense of the owner, custodian, his family or property.
c. All animals injured or killed in the street shall be considered as running at large and the Animal Control Officer shall remove all said animals and, at his discretion, take those needing medical attention to a veterinarian or to the City animal shelter. The owners of such animals shall be liable for all expense of such veterinary treatment and of the impoundment or disposal.