Tracheal Collapse

Figure 1. Schematic of tracheal collapse. Severity ranges from mild to severe (Grade 1 = 25% collapse up to Grade 4 = 100% collapse). In dogs, collapse most commonly occurs at the thoracic inlet (green arrows), where the trachea angles as it enters the chest.

Tracheal collapse is a chronic, progressive, irreversible disorder of the trachea (windpipe) and the lower airways (including collapse of the mainstem bronchi). The trachea is a flexible tube—often compared to a vacuum cleaner hose—and is supported by many small cartilage rings that help keep the airway open during breathing, movement, and coughing. These cartilage rings are C-shaped, with the open portion of the “C” oriented upward. In some dogs, the C-shaped cartilage weakens and gradually flattens. As the top portion (roof) of the trachea stretches, the rings become progressively flatter until the airway collapses (Figure 1). In some cases, the collapse can extend into the bronchi (airways leading into the lungs), causing severe impairment of airflow.

Small-breed dogs are affected most often, especially Yorkshire terriers, Pomeranians, Poodles, and Chihuahuas. Dogs are typically middle-aged or older, although younger dogs may also be affected. Dogs that are overweight or live with smokers may be at increased risk, or may be more likely to show clinical signs.

• harsh, dry cough often described as a “goose honk”
• coughing when being lifted or when a collar is pulled
• difficulty breathing
• reduced exercise tolerance
• coughing or turning blue when excited
• fainting
• a wheezy sound during inhalation

In general, the following tests are recommended to determine the degree of collapse, assess overall health, and evaluate your pet:

• Bloodwork to assess general health
• Chest x-rays (Figures 2 and 3): may support the diagnosis in some pets, help exclude other problems, and assess heart size; collapse is not always visible on routine x-rays
• Fluoroscopy (a “moving x-ray”): evaluates how the trachea changes during inhalation and exhalation (Figure 4), which matters because tracheal diameter can vary depending on breathing phase
• Endoscopy (fiberoptic camera inside the airway): provides the most detailed view of the airway lining (Figure 5) and enables collection of fluid samples for culture and analysis
• Echocardiogram (heart ultrasound) to evaluate cardiac function

Figure 2. Chest x-ray matching the diagram in Figure 1, showing tracheal collapse of differing severity in a Yorkshire terrier. Head is to the left. In the lower neck, the trachea narrows 50–75% (red arrows). At the thoracic inlet, it narrows 100% (green arrows). Within the chest, the collapse appears mild (blue arrows).

This dog has severe (Grade 4) collapse of the entire trachea (green arrows) and the bronchi (red arrows).

Figure 4a. Fluoroscopy series from the dog in Figure 3 while breathing: the airway narrows and then widens as air moves out of and into the trachea.
Figure 4b.
Figure 4c.
Figure 4d.

Figure 5a. Endoscopic images show Grade 2 (moderate) collapse (Figure 5a) and Grade 4 (severe) collapse (Figure 5b).
Figure 5b.

Medical management

Medical treatment typically includes:

• weight loss
• medications to reduce airway spasm and inflammation
• sedation to decrease coughing and anxiety

Some dogs require substantial sedation to interrupt the cough cycle, because coughing irritates the airway and triggers further coughing. Dogs should also be kept away from smoke and other pollutants; coughing may be triggered by smoke or other irritants carried indoors on clothing and hair. Dogs with infections are treated with antibiotics.

Medical therapy can help up to 70% of dogs, especially those with mild collapse. As the disease advances, some pets no longer respond adequately and need surgical or interventional approaches. Medical management generally must continue for life, even after other procedures.

Surgical / interventional management

Collapse in the neck portion of the trachea may be treated by an ACVS board-certified veterinary surgeon by surgically placing plastic rings or spirals around the outside of the trachea (Figures 6 and 7).

Another option is placement of an intraluminal stent—a spring-like device—inside the airway to keep it open (Figure 8). Stents can be used to treat collapse in the neck or within the chest without a surgical incision.

Figure 6a. Tracheal rings are available in various sizes.
Figure 6b. Rings (green arrows) are positioned around the trachea and sutured in place.
Figure 6c. Once completed, the sutured rings hold the airway open.

Figure 7a. Before ring placement, this trachea was 50% collapsed.
Figure 7b. After placement, the airway lumen appears rounder; some ring sutures are visible (green arrows).

Figure 8a. Stents are available in different sizes and materials.
Figure 8b. Immediately after placement, the stent wires are visible.
Figure 8c. After weeks to months, the stent becomes covered by the tracheal lining.

Most pets go home 1–2 days after surgery and typically return for recheck and removal of skin sutures or staples (if used). Pain is usually well controlled with medications administered by the owner.

Common recommendations after ring or stent placement include:

• continuing medical therapy to reduce pain, swelling, coughing, and excitement
• using a body harness (not a neck collar/leash)
• limiting activity for about two weeks for recovery and incision healing
• weight reduction
• avoiding smoke and other airway irritants
• using a humidifier in winter when heaters are running
• regular follow-up with your primary care veterinarian

Potential complications after treatment include:

• Ring surgery can cause coughing, bleeding, airway injury, or laryngeal paralysis. Dogs with laryngeal paralysis may require emergency procedures to keep the airway open, including surgery to “tie open” the airway or temporary breathing through a neck opening (tracheostomy). Some dogs may die immediately after surgery.
• Many dogs continue to cough for life, although the cough is usually less severe than before treatment.
• If collapse progresses into smaller airways (bronchial collapse), clinical signs may persist.
• Stents can also irritate the airway and promote coughing. If inflammation is severe, thick tissue can form in front of or behind the stent and partially block airflow (Figure 9).
• Stents spanning the thoracic inlet are at risk of fracture because of movement in this region (Figure 10).
• Stents that are too small can migrate within the trachea.

There is currently no known prevention for tracheal collapse, though reducing body weight and limiting exposure to irritants such as smoke may help. Approximately 70% of dogs managed medically alone show some improvement. About 75% improve following surgical placement of rings. Dogs older than 6 years, or those with laryngeal or bronchial disease, tend to have more complications and poorer long-term outcomes. Among dogs treated with stents, 95% improve immediately and 90% show marked improvement at follow-up. Similar outcomes are reported for rings placed in the cervical (neck) trachea. Effective control of coughing is important for good results; dogs with bronchial collapse (and therefore ongoing cough) are more likely to have problems after stent or ring placement.