Dog HarnessesDog harnesses protects the trachea by only pulling on the body and not on the neck.
"A pet harness is beneficial to dogs who may have fragile small throats or who can have difficulties breathing. A harness is best for use in brachycephalic dog breeds – which have flattened facial features – as these dogs can develop respiratory stress if too much pressure is put on their throat and neck area. A harness should always be used to walk miniature and toy dog breeds as injury to their delicate esophagus and trachea may occur through collar pressure.
A properly fitted harness will give the walker much more control over the dog particularly over pulling, lunging or jumping behaviors: Large dogs that are difficult to control should always be walked on a harness. Dogs which have not been trained to walk, or who have not been socialized with other people and animals, should be walked on a harness."