Acute heart failure in rabbits by avocado leaf poisoning.

The aim of this paper was to report an outbreak of avocado poisoning in rabbits in Salta, Argentina. Fourteen rabbits died of congestive heart failure within 30 h of ingesting fresh avocado leaves from pruned trees. They showed clinical signs of respiratory and cardiac distress. Full necropsies of four rabbits were performed and samples were collected for histopathology. The gross pathological observation included pleural and pericardial effusion, pulmonary oedema, slight ascites; the hearts appeared flabby and markedly pale. In addition, the stomach content consisted mostly of green feed with large amounts of avocado leaves. Epidermal fragments of Persea americana were identified by microhistological analysis of gastric content to get most efficiently to a correct diagnosis. Histopathological examination revealed degeneration and necrosis of myocytes and a mononuclear cellular infiltration mainly involving the myocardium and, to a lesser extent, the liver, lung and kidneys. Our observations indicate that avocado leaves should be avoided in the green diet of rabbits.