Millet can cause nitrate poisoning but not prussic acid poisoning. High nitrate levels will persist in forages cut for hay but will be reduced by one-half or so if the crop is ensiled. If you suspect high nitrates in the forage, have it tested by a forage testing laboratory. Poisoning of Horses fed sorghum, sudangrass, or sorghum-sudangrass hybrids has also been reported. The exact cause of this poisoning is not known.
Affected horses exhibit a staggering gait, urine dribbling, and aborting in pregnant mares.
There is currently no treatment for this poisoning and affected horses rarely recover. Don't feed horses any of these summer-annual species. Prepared by Marvin H. Hall and Greg W. Roth, Associate Professors of Agronomy.