The forthcoming Encyclopaedia of Equestrian Exploration documents many kinds of equine health problems. Some health problems, like colic, are very common and happen to horses in all parts of the world. But other problems are rare and only occur in small areas.

The mountains of New Mexico are one such place. In that area is a plant called "sleepy grass." Local horses learn not to touch this noxious weed. But if a horse eats this plant, it falls asleep and may remain unconscious for up to three days! The top image, taken by the US Cavalry, shows a mare which ate the dangerous grass. This plant still exists in New Mexico, where local riders and ranchers try to keep their horses away from it.

What was not known until the creation of the Encyclopaedia is that "sleepy grass" is also found in Mongolia. Long Riders travelling through New Mexico and Mongolia documented the existence of the same dangerous plant in two different countries.

Another equine health hazard has been discovered by German Long Rider Christina Puszkar. While riding solo through the Andes Mountains in Chile, Christina’s horse, Fiestero (bottom), became ill.  Horse owners in the Andes diagnosed the illness as “Mal Seco,” a localized danger which is not known in other parts of Chile.

In a repeat of the New Mexico/Mongolia discovery, Mal Seco, or ‘grass sickness’ as it is more commonly known, is the focus of a special scientific study in England. However Christina is the first Long Rider who is known to have encountered the potentially deadly disease in Chile. Luckily her horse survived.

She wrote, “Before Fiestero got sick I didn't even know that the disease existed. Even Fiestero’s breeder didn't know about Mal Seco because there are no incidents in his area. It is only the people in the mountains, whose horses have encountered Mal Seco, who know about this disease.”