Frothy bloat occurs when the cow ingests legumes, protein rich spring grass or a diet high in concentrates. A stable foam forms within the rumen, the stable foam traps gas produced by normal fermentative processes, and the gas cannot be released by eructation. Frothy bloat is commonly seen when cows are turned out onto young, lush lays and is made worse if animals are hungry when they enter the field as they tend to gorge themselves. These animals bloat rapidly and may be found dead in the field.