NIACIN DEFICIENCY RULED OUT AS GRASS SICKNESS CAUSE
straight away, so that would reduce the risk of high insulin causing laminitis.”
Bailey stresses that obesity is always unhealthy for horses. “Even though obesity does not directly appear to cause the insulin dysregulation that leads to laminitis, usually it is an indicator that insulin levels may be high because insulin promotes obesity,” he says. “Therefore, aiming for a moderate body condition is going to be the best advice for long-term management.” Bailey adds that this study underscores the influence of genetics on insulin sensitivity.
“Comparing breeds, we saw marked breed differences between the responses. Even though the Standardbreds became slightly more insulin resistant on the high-grain diet, the ponies and Andalusians were relatively insulin resistant even at a moderate body condition score and became even more insulin resistant on the high-grain diet (but not on the high-fat diet),” he says.
Taking these findings into consideration, says Bailey, “the general advice for owners of EMS-prone horses and ponies would be to avoid high-grain concentrate feeds and spring pasture which may produce the sorts of high insulin levels that drive insulin resistance and increase the risk of laminitis. When animals are in work, then using some oil or a proprietary lowglycemic supplementary feed may be the best way to supplement calories.”
As the search for the cause of equine grass sickness (EGS) continues, Scottish researchers have ruled out niacin deficiency as a contributor to the mysterious and deadly gastrointestinal disorder.
Characterized by neurological degeneration that causes paralysis of the digestive tract, EGS is a rare condition that occurs primarily in Britain but is also seen in northern Europe. Horses with acute EGS develop severe colic and typically die within 48 hours of onset; other cases unfold more slowly and horses may waste away for weeks before dying or being euthanatized. There is no known treatment and