Acute respiratory distress syndrome (ARDS) is an inherited respiratory disorder that affects the Dalmatian dog breed. Generally, ARDS is referred to as acute, life-threatening respiratory failure with high mortality rate. Among dogs, a lethal outcome of ARDS reaches almost 100%. Except for genetics, other factors that contribute to the development of ARDS have been established. Primary factors cause direct injury to the lung; such as aspiration pneumonia, pulmonary contusions, or inhalation of harmful gases. Secondary factors cause the injury of lungs through activation of systemic inflammation mechanisms. Such factors are sepsis, pancreatitis, parvovirus enteritis, nonthoracic trauma, thermal burns, or paraquat ingestion. Characteristics and Symptoms General symptoms of ARDS in dogs are difficult breathing, coughing, nasal discharge, fever, blue discoloration of the skin (cyanosis), or other signs related to underlying disease. Pulmonary manifestations include multiple foci of marked atypical hyperplasia, patchy ongoing fibrosis with myofibroblastic metaplasia, smooth muscle hyperplasia and sometimes hyperplasia of type II pneumocytes, as well as acute alveolar edema. Diagnosis is based on presenting clinical signs, thoracic radiographs, and exclusion of other causes of respiratory disease. Radiographs may show pericardial effusion, thoracic effusion, air bronchograms and free air within the lung cavity. A differential diagnosis would include pulmonary interstitial fibrosis, chronic bronchitis, kennel cough, tracheal collapse, bronchomalacia and bronchial carcinoma.