Narrowed Bronchi in Dogs

Bronchiectasis in Dogs

The trachea, or wind pipe, divides into two main bronchi, which further divide several more times into smaller bronchioles, forming the bronchial tree that feeds air into the lungs.

In bronchiectasis, bronchi are irreversibly dilated due to destruction of elastic and muscular components of airway walls, with or without accompanying accumulation of lung secretions. Dilatation and accumulation of secretions perpetuates lung damage, invite infections to settle, and compromise the lung functions in patient. American cocker spaniels, West Highland white terriers, miniature poodles, Siberian huskies, and English springer spaniels are predisposed to this condition. Bronchiectasis can occur at any age but commonly seen middle-aged or older dogs which chronic lung disease.

Symptoms and Types

• Chronic cough (moist and productive)
• Hemoptysis (coughing up blood) in some dogs
• Intermittent fever
• Lethargy
• Exercise or work intolerance
• Rapid breathing
• Difficulty in breathing normally, especially after exercise
• Chronic nasal discharge

Causes

• Primary ciliary dyskinesia (malfunction of the mucous clearing cilia in the lungs)
• Long-standing infections
• Inadequately treated infections or inflammations in the lungs
• Smoke or chemical inhalation
• Aspiration pneumonia (pneumonia caused by food, vomit, or other content being breathed into lungs)
• Radiation exposure
• Inhalation of environmental toxins followed by infections
• Obstruction of bronchi due to a foreign body
• Neoplasia of the lungs

Diagnosis

There are variable causes which may lead to bronchial inflammation in your dog. Therefore, a detailed history and a complete physical examination are essential for diagnosis. You will need to give your veterinarian a thorough history of your dog's health, the onset of symptoms, and possible incidents that might have led to this condition. Standard laboratory testing will include complete blood count (CBC), biochemistry profiling, and urinalysis. Blood gas analysis will reveal information about the functional aspects of the lungs.

These tests will be helpful in looking for infections or other changes related to the underlying disease. Your veterinarian will also take x-ray images of the chest, respiratory tract, and bronchial tubes, which may or may not show abnormalities in the architecture of the lungs, including dilatation of the bronchi.

It is hoped that x-rays will reveal characteristic abnormalities in the bronchi that are related to this disease, but that is not always the case. Other changes in the lungs pertaining to chronic infections typically can be visualized using x-rays. Long term inflammation will leave evidence that can be visually examined. More sensitive testing, like computed tomography (CT) scanning, can be used for some patients, and this test may reveal more detailed information about structural changes within lungs. Your veterinarian will also take samples of tissue and fluid from the bronchi for laboratory evaluation.