Highway Code Rule 56
Dogs. Do not let a dog out on the road on its own. Keep it on a short lead when walking on the pavement, road or path shared with cyclists or horse riders.
Section: Rules about animals (rules 47 to 58) Subsection: Other animals (rules 56 to 58)Highway Code Rule 57
When in a vehicle make sure dogs or other animals are suitably restrained so they cannot distract you while you are driving or injure you, or themselves, if you stop quickly. A seat belt harness, pet carrier, dog cage or dog guard are ways of restraining animals in cars.
Section: Rules about animals (rules 47 to 58) Subsection: Other animals (rules 56 to 58)Highway Code Rule 58
Animals being herded. These should be kept under control at all times. You should, if possible, send another person along the road in front to warn other road users, especially at a bend or the brow of a hill. It is safer not to move animals after dark, but if you do, then wear reflective clothing and ensure that lights are carried (white at the front and red at the rear of the herd).
Section: Rules about animals (rules 47 to 58) Subsection: Other animals (rules 56 to 58)