Canine Tracheal Collapse

Have you ever noticed your dog has a dry, ongoing cough or makes sounds like they're choking? In small dog breeds this problem is very common and is related to obstruction of the trachea.

Although the symptoms can be due to other conditions, such as kennel cough or choking, if they're recurring and get worse over time, your dog may be suffering from tracheal collapse.

How the trachea works

The trachea is a partially flexible tube-shaped structure that connects and allows air to travel from the nose and mouth to the lungs. As air moves in and out, it flows smoothly through our dog's trachea, allowing them to breathe.

However, when the cartilage rings that give the trachea this flexibility become deformed, tracheal collapse can occur, preventing our dog from breathing normally.

What is canine tracheal collapse?

Tracheal collapse is a chronic, progressive disease that mainly affects small breeds, such as the Chihuahua, Pomeranian, Poodle, Yorkshire Terrier, and Maltese, among others.

Tracheal collapse involves a reduction in the diameter or lumen of the trachea due to deformation or weakening of the cartilage tissue, which reduces airflow, making breathing harder.

Tracheal collapse can be congenital or acquired. In the latter case, the condition is generally linked to other chronic respiratory diseases, Cushing's syndrome, and heart problems. From the moment we notice symptoms, we should take it seriously and mention it to our vet.

Depending on the stage or severity of the collapse, the disease can be divided into four grades:

1. Grade I: a minor reduction in tracheal diameter, up to 25%. Despite this, the tracheal cartilage rings still keep their shape, so symptoms are generally mild.
2. Grade II: the deformation of the rings is more noticeable, becoming flattened due to thickening of the tracheal muscle. The reduction in tracheal diameter can reach 50%, causing labored breathing or dyspnea.
3. Grade III: the tracheal muscle thickens further, pressing down on the cartilage and flattening it almost completely. The reduction in tracheal diameter can reach 75%, causing severe dyspnea.
4. Grade IV: the most severe grade occurs when the cartilage becomes completely deformed by the pressure of the thickened tracheal muscle. This causes near-total obstruction, practically blocking airflow, with the resulting risk of suffocation.

Symptoms of tracheal collapse

Tracheal collapse usually appears in middle-aged or older dogs, and is normally diagnosed from 6 or 7 years old onward. However, it can also affect young dogs.

Below are the symptoms that could alert us that our dog has this disease, though we shouldn't confirm or rule out anything else before seeing our vet:

• Dry cough, usually along with other symptoms linked to tracheal collapse.
• Sudden coughing fits (sounding like a goose honking).
• Panting and noisy breathing.
• Dyspnea (labored or difficult breathing).
• Nausea.
• Exercise intolerance.
• Fever.
• Cyanosis (bluish skin color) or paleness.
• Syncope or fainting.

Although coughing is one of the most common symptoms and can be linked to other diseases, the dry cough of tracheal collapse usually first appears during moments of strong emotion or stress, becoming constant as the condition worsens.

These symptoms shouldn't be confused with occasional choking, either. If a dog chokes on food or an object and has serious trouble breathing in, we should stay calm and perform the Heimlich maneuver as soon as possible.

Lastly, keep in mind that overweight or obese dogs, or those living in homes with smokers, have a higher risk of developing this problem or of their condition getting worse.

Diagnosing tracheal collapse

To confirm that our dog has tracheal collapse, the vet will run a series of diagnostic tests, including an X-ray, to assess the condition of the trachea and respiratory system.

To complement this test, the vet may use different diagnostic techniques such as a tracheobronchoscopy to assess the state of the cartilage, or fluoroscopy, a very useful test for diagnosing tracheal collapse, since it lets us view the airway's dynamics in real time during the breathing cycle and pinpoint exactly where the collapse is occurring.

Unlike the first test, fluoroscopy doesn't require the patient to be under general anesthesia. Bloodwork will also let us check for eosinophilia (an increase in eosinophil count), which lets us rule out allergies or the presence of parasites (nematodes) as the cause. On the other hand, an inflammatory white blood cell count could point to pneumonia as the cause of the problem.

Since symptoms are usually fairly nonspecific, a full diagnostic workup should be planned to rule out other conditions (brachycephalic syndrome, laryngeal collapse, chronic bronchitis, infectious diseases, tumors, heartworm, foreign object, etc.).

Prognosis for tracheal collapse

Once diagnosed by a vet, treatment will considerably improve our dog's quality of life. However, the disease is progressive and chronic, so we'll need to give lifelong medical treatment, or turn to surgery.

Depending on the grade of collapse, medical treatment will consist of giving cough suppressants to ease the cough, bronchodilators to make breathing easier, expectorants to help clear secretions, antibiotics for any accompanying infections, and corticosteroids or sedatives to calm the anxiety and restlessness that make things worse.

In the most severe cases (grade IV), surgery may be needed, although not every dog is a good candidate for this type of procedure. Surgery is aimed at reconstructing the shape of the trachea or placing a prosthesis (rings) to keep the trachea open and improve breathing function.

Given the effort some dogs with advanced disease need to put into breathing, it's common for other related conditions to appear, such as tracheitis, bronchitis, pulmonary hypertension, and heart failure.

Additional care at home

Lastly, to prevent tracheal collapse from developing or getting worse, your dog will need some extra care at home:

• A low-calorie diet and weight control, especially if they're overweight.
• Stress management.
• Use of a harness — never a collar that presses on the throat.
• Avoiding intense exercise.
• Smoke-free, pollutant-free environments.
• Up-to-date vaccinations, to prevent diseases such as kennel cough.
• Avoiding sudden temperature changes.

Sources consulted: J. Rueda Hernanz, A. Fernández Santana, J. Sacido Leis, B. Pérez Delgado (1989). "Colapso traqueal." Revista AVEPA, vol. 9, no. 4. ddd.uab.cat/pub/clivetpeqani/11307064v9n4/11307064v9n4p165.pdf Catarina Sá Borges, Laín García Guasch, Jordi Manubens Grau. "Diagnóstico y manejo terapéutico del colapso traqueal y bronquial" (2016). Revista Ateuves 65, pp. 28-32. https://ateuves.es/revista-online/ateuves_65.html