Fibrotic Hardening of the Lungs (Pneumonia) in Dogs

Fibrotic hardening of the lungs, or pulmonary fibrosis, is a form of pneumonia that affects a specific section of the lungs. It is one of many types of respiratory diseases dogs can suffer from. The West Highland Terrier, among other Terrier breeds, is affected by the disorder. This disorder is characterized by the normal tissue of the lungs being replaced by fibrosis, or scar tissue. This inhibits lung capacity and function and can limit the dog’s activities, such as walking, running, and playing. Pulmonary fibrosis is hard to recognize when it is forming because there are no clinical signs in the beginning. After noticing the symptoms, and once the dog is diagnosed, it usually has progressed to where it is increasingly difficult to fully heal. The lungs are not able to properly allow the oxygen in and the carbon dioxide out, which causes great respiratory pain and distress.

Pulmonary fibrosis, or fibrotic hardening of the lungs, is a disorder of the tissue of the lungs. Normal tissue is replaced by thickened and stiff scar tissue that causes difficulty in breathing over time.

 

The symptoms of pulmonary fibrosis can be mild to severe. At the onset, symptoms may go unnoticed. Symptoms can include:

• Coughing
• Difficulty exercising
• Labored breathing
• Lethargy

Types

Pulmonary fibrosis is the most common respiratory disease in dogs and is seen mostly in the West Highland Terriers. Other respiratory diseases that the veterinarian may rule out before making the diagnosis are:

• Brachycephalic airway syndrome
• Chronic bronchitis
• Pneumonia
• Congestive heart failure
• Pleural space disease

The primary cause of pulmonary fibrosis is idiopathic. Secondary pulmonary fibrosis is caused by:

• Inhalation of pollutants
• Radiation therapy of the chest
• Medications
• Pulmonary infections
• Disorders of the connective tissues

Since the symptoms are very hard to notice in the beginning of pulmonary fibrosis, the medical professional may attribute the minor signs to aging or other disorders, such as allergies. If your dog has any of the definite symptoms, the veterinarian will listen to his breathing with a stethoscope. He may hear the lungs crackling and may notice that the dog is struggling to breathe properly.

The veterinarian will do imaging of the chest to look for specific, or interstitial, abnormalities caused by pulmonary fibrosis. The veterinarian will need to rule out chronic bronchitis because the symptoms can be similar. For this, the veterinarian will do a bronchoscopy of the airways and a cytological exam to take a closer look at the abnormal cells. Other imaging may be used at the medical professional’s discretion, such as a very informational computed tomography scan (CT scan). 

Thoracic radiography, the testing of pulmonary functions, and an echocardiography to check for hypertension may also be performed. A very expensive test which can carry a lot of weight in diagnosing pulmonary fibrosis is an open lung biopsy, although it is rarely performed. The veterinarian is able to come up with a definitive diagnosis of pulmonary fibrosis with the combination of the other tests.

Treatment is not as effective as medical professionals would desire as pulmonary fibrosis is usually diagnosed after much time has passed; the early symptoms are hard to distinguish or even be recognized as something serious. Treatment can include:

Prednisone Therapy

The use of prednisone therapy does prove effective, as it can help calm inflammation in the airways. The effectiveness, however, depends on the dog’s diagnosis and severity of the condition.

Sildenafil

Sildenafil, or Viagra, can be given to dogs to help lower lung pressure. With pulmonary fibrosis, the lungs develop a higher blood pressure because of the development of the scar tissue within the healthy lung tissue.

Other Medications

The veterinarian may prescribe specific antibiotics to counteract any infection, depending on the diagnosis and if the dog has any other conditions in addition to this disorder.

Once your dog has been diagnosed with pulmonary fibrosis, the veterinarian will give you recommendations for at-home care. With a diagnosis of this disorder, you will have to stay guarded, as the lifespan for dogs with pulmonary fibrosis is approximately one year or a little longer. If your dog is dependent on oxygen, then the time could be less. 

Every diagnosis is different, and every dog is different. Your dog may be able to survive longer with an early diagnosis and a mild to moderate level of inflammation. Your veterinarian will explain to you the prognosis of your dog and will give you advice on how to make his life more comfortable. Your veterinarian is also available if you have any questions or concerns about new symptoms or overall well-being of your fur baby.