Acetogenin-induced fibrotic heart disease from avocado (Persea americana, Lauraceae) poisoning in horses.

Poisoning by avocado (Persea americana) has been confirmed in sheep, goats, dogs, rabbits and ostriches. The clinical signs and lesions are attributed to the acetogenin, persin. Little is known regarding the epidemiology, clinical signs, lesions and therapy caused by acetogenin-induced heart damage. During the two-year study, we investigated a horse farm with six horses that often fed themselves with P. americana leaves or mature fruit pulp and skin on the ground. Two horses died, and one underwent necropsy, histopathology, and immunohistochemistry using the anti-cardiac troponin C (cTnC). Grossly and histopathologically, there was severe cardiac fibroplasia. Immunohistochemically, there was a multifocal decrease or negative expression in the cTnC cardiomyocytes' cytoplasm. Persea americana leaves were confirmed in the alimentary tract using botanical anatomy and molecular techniques. The chemical investigation by (LC-ESI-MS) revealed the presence of the acetogenins, persin and avocadene 1-acetate from P. americana. Persin was present in leaves and fruits (seed and pulp), while avocadene 1-acetate was found in leaves and fruits (seed, peel, and pulp) with a higher concentration in the pulp. Four other horses have been examined by electrocardiogram, echocardiogram and serum Troponin 1 (cTnI). To establish a causal effect of consumption of P. Americana and heart fibroplasia in horses, long-time experiments must be carried out.

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.