Crossed fat embolism in a cow with tetralogy of Fallot

A 10-month-old, female Holstein-Friesian cow with tetralogy of Fallot died during surgery for ameliorating pulmonary stenosis. Necropsy revealed no fracture of bones. Microscopically, fat emboli in the capillaries were detected in the brain, kidney, lung, adrenal gland and pituitary. In the kidney, many fat emboli were present in the glomeruli. No significant changes of the neurons were found throughout the brain, and perivascular hemorrhage and/or necrosis were rarely seen accompanying with fat emboli in the cerebral cortex. The trigger for fat embolism might be costectomy, and right-to-left shunt due to heart malformation might be attributed to crossed and systemic distribution of the fat emboli.