Tracheal collapse is a progressive disease primarily affecting toy breed dogs that results from early-onset degeneration of the tracheal ring cartilage. The trachea, or “windpipe” is made up of a series of “C”-shaped cartilage rings with a membrane (the trachealis muscle) that connects the ends of the “C”. Degeneration of the cartilage rings that comprise the trachea results loss of tracheal ring rigidity. The loss of rigidity present in affected rings, combined with stretching of the trachealis muscle, leads to flattening of the tracheal lumen (its opening), mechanical airway obstruction, and ultimately the classic “goose honk” cough and/or respiratory noise and difficulty that are characteristic of the disease. Once dogs become symptomatic for tracheal collapse, the condition is perpetuated by a cycle of chronic tracheal inflammation which exacerbates, and is exacerbated by, the coughing and inspiratory difficulty which results.
A breed predilection for tracheal collapse exists in Yorkshire Terriers, Pomeranians, Toy Poodles, and Chihuahuas. Clinical signs are generally recognized for several years prior to definitive diagnosis, which occurs around 6 years of age on average. Coughing is often associated with excitement or activity. Radiography (x-rays), fluoroscopy (“real-time” x-ray video), and endoscopy have all been used for diagnosis and assessment of tracheal collapse. Factors that may aggravate tracheal collapse include respiratory infection, heart disease, allergic respiratory disease, endotracheal intubation (as when a patient goes under anesthesia), the presence of a smoker in the household, and obesity.
Medical and surgical treatments are available for management of patients with tracheal collapse. Medical management commonly involves the use of variable combinations of cough suppressants, steroids, sedatives, antibiotics, and bronchodilators. Medical management has been reported to result in improvement in clinical signs in approximately 70% of tracheal collapse cases. Unfortunately, the condition is progressive and medical therapy does not reverse or fix the problem, so symptoms and the collapse generally worsen over time.
Surgical intervention has been recommended in patients suffering from moderate to severe tracheal collapse that are refractory to medical management. Both intraluminal (i.e. inside the trachea) stenting and placement of prosthetic (plastic) rings sutured to the outside of the trachea have been described.
Intraluminal stenting involves the use of self-expanding, metal alloy stents that support the trachea from its interior. Placement is through the oral cavity and is minimally invasive. Stents can be used to support the entire length of the trachea to the level of the mainstem bronchi, where the trachea splits into right and left lung fields. Though they can be placed with minimal invasiveness and can support the entire length of trachea, they are associated with a number of potential complications, including persistent cough (common), formation of excessive scar and inflammatory tissue, stent fracture or migration, and severe bacterial tracheal infections.
Placement of plastic rings around the outside of the trachea can be performed for patients whose tracheal collapse is primarily in the cervical (neck) region. Several (7 to 10) rings are placed surgically around the outside of the trachea (and sutured to the trachea) from the level of the larynx to the chest cavity. Dogs are good candidates for the procedure if they are middle aged (6-10 years of age) and have collapse of the trachea primarily in the cervical region without significant collapse of the intrathoracic trachea (i.e. inside the chest) or bronchi.
Although more invasive, placement of external (extraluminal) tracheal rings generally provides patients with a more favorable outcome and better long-term symptom control. Reported complications secondary to placement of extraluminal prostheses include laryngeal paralysis (about 8-10% of cases) and persistent cough (though frequency and severity of cough are generally improved when compared to pre-operative symptoms). Although not proven, early surgical treatment may slow or limit progression of the disease when compared to medical therapy and may be a factor when considering surgical intervention. Patients over 10-12 years of age often have more advanced disease and may not respond as favorably to surgical intervention. Aggressive medical therapy is recommended in these patients and surgery is considered only when medical treatment options have been exhausted.
Though tracheal collapse can be a severe and even life-threatening disease, early diagnosis and treatment can improve and maintain quality of life in affected dogs for many years in most cases. If your think your pet may be suffering from tracheal collapse, schedule a visit with your family veterinarian for a diagnosis and to discuss treatment options. And if advanced care is needed, look no further than the Las Vegas Veterinary Specialty Center.