Pneumocystis carinii pneumonia in a Yorkshire terrier dog.

A 14-month-old male Yorkshire terrier was presented to the Autonomous University of Barcelona Veterinary Teaching Hospital because of a history of chronic non-productive cough and acute dyspnea. A follow-up radiograph revealed a diffuse, bilaterally interstitial-alveolar lung disease with presence of air bronchograms. The dog died 5 h after admission with severe dyspnea. Histological sections of the necropsy specimens revealed the presence of characteristic Pneumocystis carinii cysts within alveolar spaces. A diagnosis of P. carinii pneumonia (PCP) was made on the basis of these results. To our knowledge, PCP has not been described in a Yorkshire terrier dog.