United Kingdom (U.K.) researchers recently found that grass sickness is strongly associated with low antibody levels to the bacterium Clostridium botulinum, indicating that affected horses couldn’t fight off infection. Findings from the study, which was conducted at the U.K.’s University of Liverpool (UL), 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, of UL, said, “The disease involves antibody levels in the horse, which we can influence–this opens the door to vaccination as a preventive measure.”

Grass sickness usually is fatal and presents itself in two different ways–either as severe colic, or as weight loss and difficulty eating. Both manifestations are a result of intestinal nerve damage that partially or completely paralyzes the gastrointestinal tract, rendering it unable to digest food. No U.S. cases have been found.

Proudman’s team collected biological samples from horses affected by grass sickness and control horses (without grass sickness)–blood for antibody evaluation and fecal samples for evaluation of parasite status. “We then collected a lot of questionnaire data related to the management of that horse, in particular the way it’s fed, the grazing history of that horse, any other disease that horse suffered recently, anthelmintic (dewormer) use, vaccine history, and all aspects of the horse’s management,” he said