Adonis species are grown as ornamentals in areas where the winters are not severe. Adonis aestivalis (summer pheasant's eye) has become a weed of cultivated areas and pastures in the north western States - Utah and California
Horse and pigs most severely affected. Cattle and sheep mildly affected.
Adonis aestivalis (Pheasant's eye)
The leaves and flowers contain the potent cardenolides strophanthin and cymarin.
As little as 450gms of plant material is reportedly fatal to sheep.
Leslie W. Woods, Lisle W. George, Mark L. Anderson, Dale M. Woods, Mike S. Filigenzi and Birgit Puschner. 2007. Evaluation of the toxicity of Adonis aestivalis in calves. J Veterinary Diagnostic Investigation 19:5, 581-585
Woods L.W., Filigenzi M.S., Booth M.C., et al.: 2004, Summer pheasant's eye (Adonis aestivalis) poisoning in three horses. Vet Pathol 41:215–220
Adonis is indigenous to Europe and parts of Asia, and is quite commonly grown as an ornamental in North America. There about 35 species, one
of which, Adonis aestivalis, has become a weed in some areas.
Annuals or perennials with a tap root or rhizome depending upon the species. Leaves are alternate, 2-3 times pinnately divided. Flowers are produced terminally on stems, and consisit of 5-20 petals, yellow to red in color. Some species have a dark spot at the base of each petal. It spreads via its seeds.
Vomiting, abdominal pain, and diarrhea are the commonest signs of Adonis poisoning in animals.
Symptomatic treatment for colic and diarrhea may be necessary in severe cases.
Cardiac arrhythmias, colic preceded death of horses eating the A.aestivalis in hay. Myocardial degeneration can be seen at necropsy.
Finding the Adonis plant parts in the hay and stomach contents is highly suggestive!
Adonis aestivalis (pheasant's eye)is becoming a serious weeds in parts of northen Utah, and California, where it can invade alfalfa fields, roadsides and waste ground.
1. Woods et al. Summer Pheasant's Eye (Adonis aestivalis) Poisoning in Three Horses. Vet Pathology 41: 215-220, 2004.