Tracheal Collapse in Dogs
The trachea is the large tube that carries air from the nose and throat to the small airways (bronchi) that go to the lungs. Collapse of the trachea occurs when there is a narrowing of the tracheal cavity (lumen) during breathing. This condition may affect the part of the trachea that is located in the neck (cervical trachea), or the lower part of the trachea, located in the chest (intrathoracic trachea).
Though tracheal collapse can occur in dogs of any age or breed, it appears to be more common in Miniature poodles, Yorkshire terriers, Chihuahuas, Pomeranians, and other small and toy breeds.
Symptoms and Types
Symptoms of tracheal abnormalities seem to be aggravated by heat, excitement, exercise or obesity. The following symptoms are commonly observed in affected animals:
- Dry honking cough
- Difficulty breathing
- Unproductive efforts to vomit (retching)
- Abnormally rapid breathing
- Abnormal breathing sounds
- Inabiity to perform routine exercises
- Bluish colored membranes
- Spontaneous loss of consciousness
- Congenital - existing at birth
- Chronic disease involving the airways
- More common in obese or in those animals dealing with respiratory infection or airway obstruction
You will need to give a thorough history of your dog’s health, including a background history of symptoms. After taking a detailed history, your veterinarian will conduct a complete physical examination on your dog. The routine laboratory tests will include a complete blood count (CBC), biochemistry profile, and urinalysis. The results of the complete blood count may show an abnormally high number of white blood cells (WBCs), indicative of infection.
Diagnostic imaging is an essential part of the diagnostic process, since the lungs and trachea will need to be examined as completely as possible. Chest X-ray remains a valuable tool, and may reveal a collapsed trachea as well as to help your veterinarian find the location of collapse. In some cases, enlargement of the right side of the heart may also be found.
Fluoroscopy, another advanced diagnostic technique, but one which can provide real time, active images of the internal body, may also be used for your dog. Fluoroscopy works by using an X-ray device placed in front of a fluorescent screen, with the patient on the other side of the screen, so that the physician can see the internal structure in motion, allowing for a more refined image and a more accurate assessment and diagnosis.
Your veterinarian may also take a tissue sample from the inside of the trachea for laboratory testing. This sample will be used to grow the bacteria in the tissue in order to determine if there is any harmful bacteria present in the tracheal tube, and conduct culture testing to see the types of cells that are present in the sample.
In order to grade the severity of the collapse, another technique called bronchoscopy can also be used. In this procedure, the bronchoscope, a tubular instrument with a camera attached, is threaded into the trachea and the images are retrieved and relayed onto video equipment where they can be reviewed and assessed in the process of making the diagnosis. Bronchoscopy is a more invasive method than the standard X-rays, but it can give a much more detailed view of the various abnormalities present in the tracheal tube, including foreign bodies, bleeding, inflammation, or tumors inside the airways. Bronchoscopy can also allow for estimating the degree of narrowing in the trachea, which may range from a grade-1 to grade-6 degree, measured on the basis of increasing severity. The bronchoscope can even be used to collect tissue and fluid samples from deeper within the tracheal canal for laboratory testing.
Hospitalization will be required if your dog is having severe symptoms and is not able to breathe properly. To compensate for respiratory problems oxygen therapy is administered. It is also typical to heavily sedate dogs with a collapsed trachea. This is so that they are not suffering, but also so that they are not fighting against the physical restrictions caused by the disease and against the treatments that are being used. Activity needs to be kept as minimal as possible until the dog has stabilized.
There are several drugs that can be used in the treatment of tracheal collapse. Cough suppressant medication can be used to minimize the stress related to the continuous coughing that is commonly associated with tracheal collapse, and your veterinarian will also give medication to dilate the small airways to facilitate normal breathing. Other drugs for reducing inflammation in the trachea will also be started to reduce the symptoms. In some cases, surgery may be required, especially if obstruction is a problem. However, complications are common in these patients after surgery.
Living and Management
Though complete rest is recommended for these patients during recovery, gentle exercise and adherence to a healthy diet is highly advised for reducing weight on a long-term basis. Weight reduction plays an important role in the relief of symptoms, and most dogs respond well to a well planned weight reduction program. Talk to your veterinarian or veterinary nutritionist about a weight-loss program that is best suited to your dog's weight, age, health condition and breed.
Overexcitement is discouraged in these animals, as it may precipitate a crisis for their already compromised lung function. Gentle exercise is best, and you should use a harness instead of a collar and leash, which puts undue pressure on the throat area, further compromising breathing. The prognosis for remission from the disease is good if proper treatment and weight loss can be achieved.