Summary
Tracheal collapse, also referred to as collapsing trachea is a common disorder of the windpipe in dogs. It's a progressive, inherited disorder in which the trachea's normally firm, cartilagenous rings of support are softer and less supportive than they should be.
In these cases, inspiring air in the normal act of breathing can cause the trachea to collapse on itself (much like your flimsy straw would with a thick milkshake), which typically elicits a hacking cough. This happens most often with excitement and/or exercise but severely affected dogs will suffer chronic collapse of their extra-soft tracheas.
The inflammation that results in tracheas thus affected can mean chronic discomfort for the [typically tiny] dogs affected. The mode of inheritance of this disorder has not been worked out. Multiple genes are presumably involved.
Symptoms and Identification
Observing a characteristic hacking or honking cough that occurs with excitement or exercise is the most common way milder forms of this disease is diagnosed. The disease typically worsens over time so that middle aged to older dogs are more typically affected.
With more severe cases, X-rays or fluoroscopy (akin to a real-time, moving X-ray) are used to determine the extent of the narrowing of the airway. A scope to visualize the airway directly is often recommended. Ensuring no underlying cardiac disease is present is a basic approach as well. That's why echocardiography, an ultrasound of the heart, may be undertaken in some cases.
Affected Breeds
Miniature, toy and teacup sizes of dogs are most often affected. The Yorkshire Terrier, Pomeranian and Toy Poodle are overrepresented among afflicted breeds of dogs.
Treatment
Treatment for mild cases is not always necessary. Though some training to reduce excessive excitement (which elicits symptoms) can be very effective, this step is not typically considered mandatory to help dogs maintain an excellent quality of life.
For moderate to severe cases, the administration of medications that reduce excitement and/or limit the sensitivity of the trachea can be helpful. Sedatives, bronchodilators, nebulization (or vaporization) and the occasional implementation of corticosteroids to address the inflammation of the trachea are typical approaches.
For the most severe cases, surgical implantation of a device called a tracheal stent is often recommended. It involves the advancement of a tube into the trachea to keep the trachea patent. Although this is a relatively new procedure and the statistics on its success and complication rate are still sparse, dogs whose quality of life cannot be maintained otherwise are excellent candidates for this approach.
All affected dogs should wear harnesses, not collars, to limit any additional pressure on the trachea.
Veterinary Cost
The cost for mild cases can be as low as $0 to $30 a month. More severely affected dogs requiring advanced diagnostics such as scopings and ultrasounds can expect to incur $500 to $2,000 in testing alone. Stent surgery itself can add another $2,000 to $5,000 to the bill.
Prevention
Limiting inheritance of this trait has proven difficult as the disease often doesn't make itself known until later in life after animals have been bred. Affected dogs should certainly not be bred. Severely affected dogs' lines should ideally be terminated entirely. At the very least, all first degree relatives of severely affected dogs should be sterilized.
References
Brayley, KA, Ettinger, SJ. 1995. Disorders of the trachea. In EJ Ettinger and EC Feldman(eds.) Texbook of Veterinary Internal Medicine, p. 754-766. W.B. Saunders Co., Toronto.
Canine Inherited Disorders Database