A 10-year-old, entire female Pyrenean shepherd dog was presented for acute onset of gastroenteritis. An abdominal ultrasound examination showed the presence of a suspected gall bladder mucocele. After surgery for cholecystectomy, the dog showed signs of an acute onset of respiratory distress due to bilothorax. The bilothorax responded well to medical treatment that comprised of thoracocentesis and oral steroids.