Nicotine and its related compounds are toxic to horses. The stems and leaves of many types of potato plants contain high concentrations of this alkaloid, as do the wild varieties of tobacco which grow in the western United States and Hawaii. Horses have also been known to be poisoned by domestic tobacco which has been harvested and within their reach, typically when stored in barns where they are stabled.
Nicotine affects the autonomic nervous system. In minor cases the horse may shake, shiver or twitch, particularly around the neck and shoulders. As the symptoms advance, staggering, prostration and paralysis may be evident. The heart may beat violently but produce a weak, rapid pulse. The horse may show an elevated temperature, yet the extremities will feel cold. Sometimes colic and / or labored breathing may be present.
Severe cases will usually produce a rapid onset of symptoms, followed a few minutes later by death, although some horses have been known to struggle with nicotine effects for up to several days. There is no known treatment for nicotine poisoning. :cboy:
