Underlying diseases in dogs referred to a veterinary teaching hospital because of dyspnea: 229 cases (2003-2007).

OBJECTIVE To identify the most frequent underlying diseases in dogs examined because of dyspnea and determine whether signalment, clinical signs, and duration of clinical signs might help guide assessment of the underlying condition and prognosis. DESIGN Retrospective case series. ANIMALS 229 dogs with dyspnea. PROCEDURES Case records of dogs referred for dyspnea were reviewed and grouped according to location or etiology (upper airway, lower respiratory tract, pleural space, cardiac diseases, or obesity and stress). Signalment, clinical signs at initial examination, treatment, and survival time were analyzed. RESULTS Upper airway (n = 74 [32%]) and lower respiratory tract (76 [33%]) disease were the most common diagnoses, followed by pleural space (44 [19%]) and cardiac (27 [12%]) diseases. Dogs with upper airway and pleural space disease were significantly younger than dogs with lower respiratory tract and cardiac diseases. Dogs with lower respiratory tract and associated systemic diseases were significantly less likely to be discharged from the hospital. Dogs with diseases that were treated surgically had a significantly better outcome than did medically treated patients, which were significantly more likely to be examined on an emergency basis with short duration of clinical signs. CONCLUSIONS AND CLINICAL RELEVANCE In dogs examined because of dyspnea, young dogs may be examined more frequently with breed-associated upper respiratory tract obstruction or pleural space disease after trauma, whereas older dogs may be seen more commonly with progressive lower respiratory tract or acquired cardiac diseases. Nontraumatic acute onset dyspnea is often associated with a poor prognosis, but stabilization, especially in patients with cardiac disease, is possible. Obesity can be an important contributing or exacerbating factor in dyspneic dogs.