Guide to Poisonous Plants

Avocado

Botanical Name: Persea americana Mill. (USDA, ITIS), Synonyms: Persea gratissima C.F. Gaertn., Laurus persea L., Persea nubigena L.O. Williams, Persea persea (L.) Cockerell

DescriptionThe avocado tree can grow to 66 ft in height with elliptical to egg-shaped leaves that are 4-12 inches long. The Mexican variety typically has smaller thin-skinned fruits while the Guatemalan varieties are characterized by medium to large fruit with rough, thick, woody skins. Hass avocados, popular in the US, are Mexican-Guatemalan hybrids.Plant FamilyLauraceaeDistributionAvocados grow in tropical and mediterranean climates throughout the world.Animals AffectedToxicity following the ingestion of avocado has been observed in cattle, horses, goats, sheep, rabbits, guinea pigs, rats, mice, canaries, budgerigars, cockatiels, ostriches, chickens, turkeys, and fish.Toxic PrincipleThe ingestion of fruit (usually immature), leaves, stems, bark, and seeds has been associated with poisoning in animals. The toxic principle identified in avocado is persin. When isolated from leaves this compound caused mastitis in lactating mice at 60 mg/kg and myocardial necrosis at 100 mg/kg. Sheep fed 2.5 g/kg body weight for 32 days developed cardiac insufficiency. Guatemalan varieties are more commonly associated with symptoms and are thought to be more toxic.DescriptionThe avocado tree can grow to 66 ft in height with elliptical to egg-shaped leaves that are 4-12 inches long. The Mexican variety typically has smaller thin-skinned fruits while the Guatemalan varieties are characterized by medium to large fruit with rough, thick, woody skins. Hass avocados, popular in the US, are Mexican-Guatemalan hybrids.Gastrointestinal SystemColic and diarrhea.Cardiovascular SystemCardiomyopathy, pulmonary edema, and necrosis of myocardial tissue.Respiratory SystemIn birds, acute respiratory distress and sudden death have been observed following the consumption of avocado. Caged birds appear to be more sensitive.Integumentary SystemHorses develop edematous swelling of the lips, mouth, tongue, eyelids, head and neck which may result in respiratory distress.DiagnosisDiagnosis is based on history of exposure to avocado and clinical signs consistent with toxicity.TreatmentNSAIDS and analgesics may improve mastitis symptoms. Symptomatic treatment of cardiac insufficiency.Special NotesExposure of livestock and horses to abandoned avocado orchards should be avoided.

Avocado Map

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