Endotoxemia, or the presence of microbe-derived toxins in the bloodstream, is "one of the most severe and ubiquitous disease processes in horses," noted Gal Kelmer, DVM, MS, Dipl. ACVS, ECVS, lecturer in equine surgery at The Hebrew University of Jerusalem, Israel, at the 2009 American Association of Equine Practitioners convention, held Dec. 5-9 in Las Vegas, Nev.

Kelmer explained that endotoxemia causes delayed gastric (stomach) emptying, which can cause the stomach to retain acidic contents and cause or worsen gastric ulcers. At worst, delayed gastric emptying can lead to accumulation of reflux material and gastric rupture.

Since many effects of endotoxemia are due to the oxidative damage it causes, antioxidants such as dimethyl sulfoxide (commonly called DMSO) might have a protective effect. Kelmer and colleagues at the University of Tennessee investigated the effects of DMSO on delayed gastric emptying caused by experimentally induced endotoxemia, and they unfortunately found that it did not improve the condition.

"DMSO may be less effective in the management of endotoxemia in horses than was previously thought," summarized Kelmer