Common Name
Buckeye, horse chestnut
Botanic Name
Aesculus spp.
Plant Family
Generally prefer rich moist soils, woodlands, etc., but some species have adapted to drier conditions. Horse chestnuts are frequently planted as ornamental shade trees.
Animals Affected
Cattle, sheep, horses, swine, chickens and humans have been poisoned naturally and experimentally by various species of buckeye.
Toxic Principle
The glycoside aesculin and fraxin and possible a narcotic alkaloid, present in the young growing sprouts, leaves and seeds are thought to be responsible for toxicity in animals. Experimentally, as little as 1/2% body weight of ground nuts fed to calves produced severe poisoning. The nectar and sap of A. californicum is known to kill honey bees that feed on it, so much so that bee keepers recommend moving hives during the flowering period of the California buckeye. Poisoning of livestock generally occurs when animals eat the leaves and sprouts of the buckeye as they generally leaf out before other plants in the spring.
Aesculus species are common small to medium sized shrubs or trees with large palmate leaves, white to red flower spikes born terminally on the branches, and characteristic spiny or smooth fruit capsules containing 1-3 shiny brown nuts when ripe. The following Aesculus species are reportedly toxic to animals; A. glabra ( Ohio buckeye), A. californica ( California buckeye), A. pavia (Red buckeye), A. octandra (Yellow buckeye), and the introduced species A. hippocastanum (Horse Chestnut). The buckeyes and horse chestnut are not related to the edible chestnut (Castanea spp.
Colic has been the main problem reported in horses. Vomiting and abdominal pain may be seen in other animals eating buckeyes. Hyperglycemia, glucosuria and proteinuria appear to be consistent features of severe poisoning.
There is not specific therapy for buckeye poisoning. Laxatives may be given to help remove the ingested plant as rapidly as possible from the intestines. Supportive intravenous fluid therapy with calcium gluconate and dextrose may be beneficial.
Nervous System
Affected animals initially show muscle twitching, weakness and a peculiar "hopping" gait, especially involving the hind legs. In severe cases of buckeye poisoning muscle tremors rapidly progressed to muscle spasms and recumbency. These spasms that may occur every 30 seconds can be induced by handling or stressing the animal. A dorsalmedial strabismus occurs in severe cases.
Access to and consumption of the leaves or seeds along with the neurologic signs is highly suggestive!
Special Notes
Horse chestnuts (Aesculus species) are totally different from the edible or sweet chestnut(Castanea species) References 1. Harwood DG, McPherson GC, Woodger NGA. Possible horse chestnut poisoning in a Cashmere goat. Vet Record 2010. 167: 461-462. 2. Casteel SW, Johnson GC, Wagstaff D. Aesculus glabra intoxication in cattle. Vet Human Toxicol. 1192. 34: 55. 3. Williams MC, Olsen JD. Toxicity of seeds of 3 Aesculus species to chicks and hamsters. Am J Vet Res 1984. 45: 539-542.
Leaves and flowers of yellow buckeye
Horse chestnut flowers
Horse chestnut seed capsules
Horse chestnut (Buckeye) fruits