Idiopathic Pulmonary Fibrosis (IPF) is a chronic disease observed in middle-aged to old terriers, mainly in the West-Highland, and occasionally other breeds. Dogs present dyspnea, tachypnea, exercise intolerance, and very often cough. Pulmonary auscultation frequently reveals mild to very severe crackles. Final diagnosis is based on exclusion of other chronic respiratory diseases (including imaging and bronchoscopy) but ultimately relies on histopathological examination of affected lung tissue.
A similar disease afffects humans mainly over 50 years of age. It is a progressive and ultimately fatal lung disease, there is no known cause, no approved treatment and no cure. IPF is thought to evolve from undefined alveolar injuries produced by infectious, oxidative, or immunologic triggering agents resulting in a recurring sequence of injury, repair, and subsequent fibrosis. Susceptibility is apparently genetically determined as a number of familial cases has been documented.Some studies have led to the identification of candidate genes including genes encoding surfactant proteins, the major histocompatibility locus and the telomerase complex. But studies in humans are complicated by the late age of onset of the disease making it difficult to collect cohorts suitable for genetic analysis. The dog model is quite suitable to help discovering other susceptibility genes to that condition.
A research program has been initiated in dogs to:
– Identify biomarkers (specific molecules in blood or in the alveolar lavage fluid that would help diagnose the disease without lung biopsy)
– Identify a possible underlying genetic defect in terrier breeds
– Gain knowledge about the mechanisms of lung fibrosis progression, that might lead to a treatment for this disease currently incurable
Letter to Breeders and Owners