CT features and short-term outcome in cats presenting with pyothorax

Objectives: The purpose of this retrospective, descriptive study was to assess CT findings and short-term outcome of cats with pyothorax presented to a referral hospital. Methods: Thoracic CT studies of 41 cats with pyothorax comprising pre-contrast lung and soft tissue reconstructions and post-contrast soft tissue reconstructions were blindly reviewed by two European College of Veterinary Diagnostic Imaging (ECVDI) board-certified radiologists and a third-year ECVDI resident, referencing a predetermined list of imaging features. Clinical outcomes, including treatment options, survival to discharge and length of hospitalisation, were recorded. Results: All cats (100%) had pleural effusion. Common imaging findings included intrathoracic lymphadenomegaly (85%), pleural thickening (85%), presence of pannus (81%) and evidence of pneumonia (49%). Pulmonary abscessation was suspected in 22% of cats and foreign bodies in 12%. Of the 41 cats, 20 were managed medically, 20 underwent surgery and one had unsuccessful medical treatment followed by surgical intervention. The median duration of hospitalisation was 7 days, and 36 cats survived to discharge. Conclusions and relevance: This study demonstrates that cats with pyothorax commonly have marked changes on CT that involve multiple thoracic compartments. Our study population highlights that feline pyothorax can have a good short-term outcome when managed either medically or surgically.