CONDITION
Idiopathic Pulmonary Fibrosis in West Highland White Terriers
Idiopathic pulmonary fibrosis is a progressive condition in which the delicate tissue of the lungs becomes thickened and scarred over time, making it harder for oxygen to pass into the bloodstream. In West Highland White Terriers, this pattern appears more frequently than in other breeds, though the underlying trigger remains unknown. The scarring tends to be gradual and irreversible. Owners often notice a cough that persists over weeks or months, sometimes accompanied by faster breathing or reduced stamina during walks. The signs can be subtle at first and may be mistaken for other respiratory conditions. Some dogs show these changes in middle age, while others remain unaffected until later in life. This page explores what signs may be observed, what is understood about the changes occurring in the lung tissue, how the condition is investigated through imaging and other tests, and what approaches exist to manage symptoms and slow progression. The course varies between individuals, and the information here is intended to support understanding rather than predict what will happen in a particular dog.
Why this matters now
This condition tends to be recognised in middle-aged to older West Highland White Terriers, often between six and nine years, though younger and older dogs can also be affected. The breed carries a much higher risk than others, suggesting a genetic component that has not yet been fully mapped. There is no clear link to environmental exposures, infection, or lifestyle, and many affected dogs have lived in varied circumstances.
The scarring accumulates slowly, often over months to years, and does not reverse. Some dogs show steady, gradual worsening of breathing effort and exercise tolerance, while others may plateau for a time before further decline. The rate of change varies widely between individuals, and it is not possible to predict the trajectory reliably from early findings alone.
Signals & patterns
Early signals
Persistent dry cough
A cough that continues for weeks without obvious cause, often described as harsh or hacking, and not typically productive of mucus. It may be more noticeable after excitement, exercise, or when the dog is resting at night.
Slightly faster breathing at rest
The breathing rate when the dog is calm may be a little higher than before, or the chest may appear to move more noticeably. This change can be subtle and may only become apparent when comparing the dog's behaviour over time.
Reduced stamina on walks
The dog may tire more quickly than usual, stop to rest more often, or choose shorter routes. The change is often gradual enough that it can be attributed to ageing or weather until it becomes more pronounced.
Occasional wheezing or crackling sounds
Fine crackling noises may be audible when listening closely to the chest, particularly after exertion. These sounds reflect stiffness in the lung tissue and the way air moves through scarred areas.
Later signals
Laboured breathing with minimal effort
The dog may breathe more rapidly or with visible effort even when lying down or moving around the house. The chest wall may show an exaggerated rise and fall, and the dog may adopt a posture that makes breathing easier, such as standing with the elbows out.
Bluish tinge to gums or tongue
In more advanced stages, the mucous membranes may take on a greyish or bluish colour, particularly after activity, reflecting reduced oxygen levels in the blood. This change is not always obvious in all lighting conditions.
Weight loss despite normal appetite
The increased effort of breathing can raise the body's energy demands, and some dogs lose condition even when eating well. Muscle mass over the spine and hips may become more prominent.
Click to read about the biological mechanisms
How this is usually investigated
Options & trade-offs
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