Bloat is a common gastrointestinal disorder that occurs in cattle and ruminants. It is caused by cattle not being able to belch or release gases that are produced during the normal microbial fermentation process that occurs in the rumen. Without release of the trapped gas, it puts alot of pressure on the diaphragm and lungs due to the resulting expansion of the rumen; without treatment this can lead to suffocation and death due to lack of oxygen.

There are several types of bloat that affect cattle. Frothy bloat is the most common. It is caused by ingestion of too much grain (feedlot bloat) or forages with high levels of soluble protein (pasture or legume bloat), which lead to the development of foam in the rumen. The presence of this foam blocks the esophageal entrance, preventing the cow from being able to expel the excess gas. Most cases of frothy bloat occur in the spring, with the presence of lush grass pastures. During the fall, bloat risk increases again with onset of cooler weather, heavy morning dew and development of frost.

Another, less frequent cause of bloat in cattle is free-gas bloat. Free-gas bloat occurs due to internal damage that causes blockage of the cow's cardia or esophagus. It can also be caused by depression of rumen movement.