Pulmonary fibrosis (Westie lung disease)
Definition: Idiopathic pulmonary fibrosis, also called Westie lung disease, literally means scarring of the lungs. It is similar to the same disease in humans. The lung scarring occurs in the tissue of the lungs called interstitium, which supports the structure of the lungs (air sacs or alveoli). Pulmonary fibrosis causes the lung tissue to scar and lose its elasticity and become stiff so that oxygen is prevented from entering the blood stream. Compared to other breeds, the Westie seems predisposed to the disease as do the Norwich and Cairn to a lesser extent.
Causes: Actually the exact origin of the disease is unknown. Presumably, pollutants, ingested and inhaled chemicals, dust and gazes play a role in inducing pulmonary fibrosis, and alveolitis and congestion of the lungs seem to predispose dogs to PF. Research and observation seem to show a link between PF, allergies and disorders of the immune system. Preliminary studies and the fact that Westies are more affected than other breeds of dogs seem to point to a genetic basis but the proof remains to be made.
Symptoms: Dogs are affected differently and at varying rates. A Westie can suffer from this condition a long time before the characteristic symptoms appear. The diagnosis of PF is usually made around 10 years of age. At first, the dog seems to loose its stamina and tires easily. A dry cough is often present so that the disease is often misdiagnosed for bronchitis. As the disease progresses and the damage to the lungs become more severe, there is rapid breathing, shortness of breath and difficulty in breathing which become the major symptoms that can lead to death. Characteristic crakled sounds heard on lung auscultation. Complication involves pulmonary hypertension and enlargement of the heart. The immediate causes of death are often a heart attack, right heart failure, embolism in the lungs, stroke and lung infection brought on by the disease.
Diagnosis: It is suspected that there are more Westies affected than we know of, partially because the diagnosis is difficult to make, and partially because the disease is unknown to many veterinarians and require a special expertise. Tests are needed to differentiate the disease from other presenting similar symptoms. First, a complete physical exam with careful auscultation is necessary. The full proof diagnosis requires usually a lung biopsy, but this is an invasive procedure which can be risky for the dog.
The other diagnostic tests may include:
-Chest X-Ray which can show the changes in the lungs. Have the X-Rays seen by a specialist in radiology
-A complete blood count
-Computed tomography is promising because it allows the detection of the disease early when the treatments have the best chances of success and shows the stage of the disease. Unfortunately, it is very expensive and may be found only in larger veterinary hospitals
Treatment: Once scar tissue has formed in the lung, it cannot be removed surgically or with medication. Specific treatment has a better chance of success if initiated early in the disease. According to Dr Corcoran, a worldwide authority in this domain, the response to treatment is usually poor and there is inevitable and progressive deterioration.
Medication may include:
-Glucocorticosteroids like Prednisone, Vanectyl
-Azathioprine (Imuran), cyclosphosphamide
According to some owners of Westies affected by this disease, it is also recommended to keep the house cool, around 60 F since heat makes the symptoms worse. Keep the dog in air condition in the summer.
Prognosis: The disease varies from dog to dog. For some, the disease progresses slowly and gradually over months or years, while for others there is a rapid progression. In other cases, it may stabilize for a period of time. The course is unpredictable. The ultimate prognosis is very poor and the disease is ultimately fatal.
What you can do if you have a Westie diagnosed with pulmonary fibrosis:
-Monitor your dog for signs of respiratory problems
-Communicate with your breeders and other Westie owners in order to develop a better knowledge of this disease.
-Inform your veterinarian of the disease and the research being done.
Author: Monique Courtois