People who are thinking about exercising their dog while they ride a bike should invest in a bungee-style dog collar and lead, as this is "perfectly humane".
That is according to Dr Pete Wedderburn, writing for the Daily Telegraph, who was responding to a reader who said her neighbour rides her bike with the dog running behind her.
The reader was concerned that this type of exercise, as well as jogging with a dog, is not good for the animal.
Dr Wedderburn said it would be unfair to attach a dog to a bike with a standard lead and that this sort of exercise will depend on the individual dog and their fitness level.
He wrote: "A bungee-type lead, which is elasticated to prevent sudden harsh pressure to the dog, combined with a body harness rather than a neck collar, can be perfectly humane.
"Some dogs love this type of exercise, and will happily run for an hour or more."
He added that as long as the owner is paying attention to the dog and its welfare, there is no problem with this sort of exercise.