Researchers in the United Kingdom recently advanced scientific knowledge of equine grass sickness with a three-year study that found the disease to be strongly associated with low antibody levels to the bacterium Clostridium botulinum. Findings from the study, which was completed at the University of Liverpool, funded by The Home of Rest For Horses, and published in the Equine Veterinary Journal might lead to routine vaccination against C. botulinum in U.K. horses.

Chris Proudman, MA, VetMB, PhD, CertEO, FRCVS, senior lecturer in equine surgery at the U.K.’s University of Liverpool, said, “The research provides some good evidence that the disease is associated with C. botulinum, and from a horse owner’s point of view, probably the most important take-home message is that antibody levels in the horse, which we can influence–this opens the door to vaccination as a preventive measure.”

Grass sickness was first identified around 100 years ago, and scientists have since struggled to understand the disease and identify its cause. The disease usually is fatal and presents itself in two different ways–either as severe colic or weight loss and difficulty eating. Both manifestations of grass sickness are as a result of nerve damage to the intestine that partially or completely paralyzes the gastrointestinal tract, rendering it unable to digest food.

According to Proudman, no cases have been found in the United States. He hypothesized that one possible explanation for the regional and geographical distribution of grass sickness is that the causal toxin is carried on a plasmid (a small, independently replicating, piece of DNA outside a cell’s nucleus that can be transferred from one organism to another) within C. botulinum Type C. “It could be that the Type C C. botulinum in the United States might not have this particular plasmid,” he said