Persea americana

Abstract

DISTRIBUTION: Cultivated mostly for human consumption in the temperate, frost-free subtropical regions of the country.

BOTANICAL DESCRIPTION: The Guatamalan race is potentially the most poisonous of the three avocado races. Examples of cultivars of this race are: Hass, Fuerte and Nabal.

TOXIC PRINCIPLE: An unidentified cardiotoxin and persin, which induces a non-infectious mastitis and agalactia in lactating females.

SYSTEMS AFFECTED: Cardiovascular system.

CLINICAL SIGNS: Clinical signs associated with heart failure, such as: • respiratory distress, • coughing, • increased respiratory and heart rates, • cardiac arrhythmias, • anasarca of the ventral neck and brisket (in horses also severe oedematous swelling of the head) and • cyanotic mucous membranes.

Other clinical signs include: • general weakness, • recumbency, • anorexia, • a non-infectious mastitis and • a drop in milk production.

Although the ripe fruit is eaten by man, there are several reports of poisoning in animals due to ingestion of leaves, green fruit, seed or bark. These animals include: cage birds, horses, goats, sheep, rabbits and ostriches.

NECROPSY: Findings consistent with cardiac failure: • Pulmonary oedema • Hydrothorax • Hydropericardium • Slight ascites • Anasarca • Congestion of the liver. The heart may be slightly pale and flabby. Nephrosis.

HISTOPATHOLOGY: Degeneration and necrosis of myocardial fibres.