An 11-year-old, castrated, domestic short-haired cat was presented for respiratory distress.
The patient was presented to the primary veterinarian in acute respiratory distress. Pleural effusion was noted on imaging, and 220 mL of opaque, milky white fluid (with small lymphocytes on cytology and 3.5 g/dL total protein) was removed via left-side thoracentesis. The top differentials were pyothorax or chylous effusion. The cat was referred to a specialist for further evaluation of suspected chylothorax.