Tracheal collapse

The trachea is the channel in which air travels to the lungs. It is made up of multiple semi-firm cartilage rings in the shape of a "U". The dorsal side is made up of a membrane that "closes the U" of these cartilage rings. 

We do not yet know the reasons that cause the trachea to collapse. It often happens at a middle or older age and mostly affects toy or miniature breeds. The cartilage rings lose their stiffness, which, with time, leads to stretching of the dorsal membrane and causes its collapse. The collapses are often at the cervical or intra-thoracic regions of the trachea. 

 

Clinical sign

The clinical sign most commonly noted by owners is an occasional cough that increases in intensity and becomes chronic. It often occurs when pressure is applied to the trachea. The problem increases with nervousness, physical effort, or anxiety. The mucous membranes (gums) can go from a normal rosy color to a blue hue when the pet experiences acute respiratory difficulty.   

Diagnostic tests

The diagnostic tests most commonly used include a radiography and fluoroscopy. The radiography allows us to take static shots of the trachea by inhaling and exhaling. The fluoroscopy on the other hand is a "moving" x-ray that allows us to to evaluate changes in the trachea in real time. The bronchoscopy (introduction of a small camera in the trachea and bronchi) is a diagnostic tests that permits us to evaluate the degree of the tracheal collapse. We use this test less often as it presents many risks when the animal is in an acute phase. 

Treatments

Treatment depends on the pet's condition. In the acute phase, the first step is to calm the pet, reducing the anxiety that is causing the problems. Diazepam and butorphanol are the drugs most often used. If the patient is experiencing severe respiratory difficulty and the mucous membranes are blue, it is ncessary that he be put in an oxygen cage. Corticosteroids will also be administered to reduce oedema in the trachea. Lastly, bronchodilators are administered to reduces spasms present in the smaller respiratory airways. 

The same medication will be used for the chronic form as in the acute one. The only difference will be in the frequence of administration and the dosage. Drugs will only be given as needed. Antitussive agents, such as dextrometorphan, butorphanol, and hydrocodone, are also used. Low-dose corticosteroids can also be prescribed.