Researchers Look at New Pathogen in Equine Grass SicknessBy Kentucky Equine Research Staff · January 17, 2010

Equine grass sickness (EGS) is characterized by polyneuropathy and ultimately death, sometimes in as little as two days following onset of illness. The disease is thought to be caused by toxins produced by Clostridium botulinum, type C, a soil-borne bacterium. Scientists theorize that ingested bacterium spores produce the toxin in the gastrointestinal tract, wreaking havoc on the digestive environment. Paralysis of the gastrointestinal tract is a classic sign.

To determine if Clostridium perfringens contributes to equine grass sickness, researchers at the University of Edinburgh set out to determine if the prevalence of C. perfringens is greater in the ileum and feces of horses diagnosed with EGS than control horses. Three control populations were used: healthy grazing horses; horses without gastrointestinal disease; as well as pasturemates and horses with colic but no EGS.

The prevalence of C. perfringens in feces as determined by both culture and ELISA was significantly higher for EGS horses than for healthy grazing controls. Also, the prevalence of C. perfringens in ileal contents from EGS horses was greater than that for horses with nongastrointestinal disease, and EGS cases had a significantly greater prevalence of C. perfringens in feces than pasturemates and colic horses.

Researchers concluded that "the use of a commercial ELISA to detect fecal C. perfringens may be diagnostically beneficial when differentiating EGS cases from colic cases, although further work is required to fully evaluate its potential."

The full article, titled "Prevalence of Clostridium perfrigens in faeces and ileal contents from grass sickness affected horses: Comparisons with 3 control populations," was published in the September, 2010 issue of Equine Veterinary Journal.