Collapsing Trachea
Tracheal collapse is progressive disorder resulting from weakened cartilage of the trachea (windpipe). The disease can start in young to middle age dogs, but generally is most pronounced in older small and toy breeds. Yorkies, Pomeranians, Pugs and Mini and Toy Poodles are breeds with the highest risk. However, medium and large breed dogs can occasionally be affected as well.
Symptoms:
Most owners notice a mild intermittent “honking” cough that is generally worse with excitement and exercise. As the disorder progresses, some patients will develop significant airway obstruction and may present with severe breathing difficulties. Patients with really advanced disease may turn blue or collapse during the coughing episodes.
Testing:
A physical examination may reveal a “honking” cough particularly when pressure is applied to the base of the neck. X-rays of the chest may show evidence of tracheal collapse. Since a cough takes only a split second, it is sometime difficult to diagnose a collapsing trachea on plain x-rays. Fluoroscopy, or moving x-ray, is the diagnostic test of choice. Fluoroscopy records for several seconds up to about 1 minute. This allows the doctor to evaluate the entire airway during rest and during periods of coughing in an awake patient. Bronchoscopy, or scoping of the airways and lungs, can also be used to the make the diagnosis. However, bronchoscopy requires general anesthesia.Treatment:
In the early stages, medications are usually recommended. Weight loss, elimination of second hand smoke and limiting exposure to substances that cause allergies are simple issues that can significantly improve a patient’s quality of life. Cough suppressant, anti-inflammatories, and airway dilators are also commonly used for patients with progressive signs. Asthma type inhalers have been gaining popularity and are often preferred since it eliminates the whole body side effects associated with many of the oral pills. Patients with advanced disease are best managed with surgery or a tracheal stent. Surgery involves the placement of plastic rings round the outside of airway to add support and ideally eliminate any collapse. Surgery is generally effective, but significant complications are possible particularly if the airway is collapsing within the chest rather than in the neck. In recent years, tracheal stents have been used with increasing frequency. Tracheal stents are based on human heart stents for clogged arteries. Much like a heart stent opens a blocked blood vessel; a tracheal stent opens a collapsing airway by supporting it from within. The location of the tracheal collapse is important when planning a stenting procedure. Some locations are more amenable to stenting than others. Because dogs range in size from a few pounds to well over 100 pounds, particular measurements must be performed to determine the appropriate size stent. With the patient under anesthesia, a stent can then be placed under fluoroscopy (moving x-ray) without any surgical incisions. Stents immediately eliminate the obstruction created by the collapsing trachea. Patients are carefully screened to ensure that a tracheal stent is the most appropriate treatment and is most effective when all medical options have been exhausted. Complications, although rare, can occur and may include scarring of the airway, infection and movement of the stent.