Collapsed Trachea
The trachea ( or windpipe) of a Yorkie tends to be somewhat weak. Aging or physical trauma to the windpipe may cause the trachea to collapse in one or more areas. One reason you should never use a collar with a leash for your Yorkie. Always use a good harness.
Symptoms of a collapsed trachea are a dog coughing hard, especially after exercise. This coughing becomes worse as time passes, especially in an older dog. A collapsed trachea can also be caused by the tube that a veterinarian may use for administering anesthesia needed for certain procedures.
The only treatment for a collapsed trachea is surgical. If you are concerned that your Yorkie has a collapsed trachea, consult with your veterinarian for options.