A 4-year-old male German Shepherd dog was presented with a history of compromised respiratory function, lack of appetite, and weight loss. A physical examination suggested intra-thoracic pathological lesions, and was later confirmed by radiography and Computed tomography. Intrathoracic granulomatous mass as well as lesions in other organs were found in the autopsy.. Microbiological analysis revealed Actinobacillus lignieresii as a causative agent of the disease.