Collapsing trachea (or collapsed trachea) is a common condition that causes coughing in small and toy breeds of dogs.
Let us start with an explanation of how the dog breathes, The respiratory system is basically comprised of the opening in the nose, the sinuses, the larynx (air passage containing the vocal cords), the trachea (wind pipe), the bronchial tubes, and the lungs. It has a dual purpose in the dog: to remove carbon dioxide from the body replacing it with oxygen, and to act as a cooling system. Since dogs do not have sweat glands they cannot perspire to lower their body temperature. By breathing faster, warm air from the body is exchanged with cooler air from outside.
The act of breathing is accomplished by the actions of the rib muscle and the movement of a large internal muscle called the diaphragm. The diaphragm separates the chest from the abdomen. Movement toward the abdomen causes the pet to breathe in fresh air. As the pet inhales, fresh air moves through the nose and larynx to the trachea. This rigid tube is supported by tough rings of cartilage. It carries the air to the bronchi, which in turn supply the lungs.
What is a collapsed trachea?
The trachea is supported by tough rings made of cartilage. Occasionally, the trachea will lose its rigidity and collapse while the dog is breathing. For unknown reasons, the cartilage rings weaken and the trachea no longer has proper support. The collapsing trachea syndrome is most often seen in toy breeds, especially Toy Poodles over the age of five.
What are the symptoms?
The symptoms of this syndrome depend on the severity of the deterioration. Usually, the dog will have difficulty breathing, especially during exercise. The deeper the pet tries to inhale, the more the trachea collapses, further restricting air flow (similar to sucking on a straw too hard). The pet appears to tire easily as it becomes short of breath. Dogs with a collapsing trachea will generally cough as if trying to clear the airways, and occasionally this cough will sound like a goose honk. In very severe cases, the tongue and gums will appear blue as breathing becomes restricted.
What are the risks?
Most dogs suffering with the collapsed trachea syndrome live normal - but restricted - lives. Activity is generally limited because the ability to breathe deeply when exercising is hindered. Left untreated, the restricted air flow can put undue stress on the heart and lungs as they try to compensate for the inability to breathe properly. Obese dogs are at greater risk than others.
What is the management?
Examination with the fingers and radiographs (x-rays) will generally confirm the diagnosis. Depending upon the severity of the condition, medications will help. Veterinarians usually prescribe drugs to help dilate the airways. The coughing is controlled by cough suppressants such as Torbutrol. If the pet is obese, we suggest a stricter diet. Finally, activity should be restricted and not encouraged. Dogs with collapsing tracheas should wear harnesses instead of collars in order to take any pressure off of the trachea. With the help of medication and modification of lifestyle, the collapsing trachea can be controlled but seldom cured. In severe cases, surgery to help open the airways may be beneficial, but most cases are managed medically not surgically.