Causes of bovine bloat and treatment options neighbors 6 gas laws


As we approach the holiday season, most of us will have the opportunity to feel bloated after a meal. Although this problem is only a temporary discomfort for people, bloat in cattle is a more serious issue. Since bloat can have more than one cause, being able to identify what caused the bloat will impact treatment success and prevention.

While there are multiple things that can cause bloat, there are two main categories that all causes fall in. These are frothy bloat and free gas bloat. Both are caused when the animal is unable to burp out the gases that are naturally produced by digestion. Frothy bloat occurs when a feedstuff causes the gases to become entrapped in bubbles, like a foam. Because the foam cannot be burped out, the foam continues to build and the animal bloats. Feeds like alfalfa and a high grain diet can lead to frothy bloat if they are introduced to the animal suddenly, therefore it is best to build these into the ration over the course of a few weeks.

Free gas bloat occurs when the animal is unable to burp. Often this is because the nerve that is involved in the burping process, the Vagus nerve, is inflamed. This inflammation is associated with other injuries, such as chronic pneumonia or damage to the pharynx. Other times it can occur because there is a partial obstruction of the esophagus, such as an abscess in the neck. Lastly, cattle cannot burp when they lie on their back. That’s why healthy cattle that lie or fall down with their feet uphill will die if not helped upright, because they continue to digest feed and produce gas even if they cannot burp that gas out.

With either type of bloat, the most critical factor in treating cattle is to let the bloat off. The best way to accomplish this is to pass a stomach tube, allowing the gas to escape from the rumen. Use a soft, flexible piece of tubing one-half inch in diameter as a stomach tube. It is also helpful to have a metal tube to place in the mouth so the animal cannot chew through the stomach tube. This metal tube, called a speculum, should be completely smooth and not have any rough or sharp edges.

When passing a stomach tube, apply gentle pressure to the tube while slightly rolling it both directions. This will help the tube pass through two points of resistance, which are at the entrance to the esophagus and at the entrance to the stomach. Don’t try to force the tube down the throat, as this can cause damage to esophagus, or it can be a sign the tube is not in the stomach but rather the lungs. Passing a tube rectally will not help with bloat in cattle, as the bloat is in the stomach and not the intestines.

Once you reach the stomach you will be able to smell the rumen gas coming through the tube. There will be no question if it is in the right spot, as it has a pungent odor. If the bloat is from free gas, the gas will race out of the tube and the animal will rapidly deflate like a balloon stuck with a needle. In addition, take the animal’s temperature. If it has a fever, administer a prescription-strength antibiotic to help address the primary, infectious cause of the bloat. An over-the-counter drug, such as penicillin or oxytetracycle 200, will be insufficient. Because of this, have a good relationship with a veterinarian before you encounter this situation.

If the gas is a frothy bloat instead of a free gas bloat, only minimal gas will escape through the stomach tube. If this is the case, move the tube within the stomach to remove the larger pockets of gas, and then administer the medication proloxalene through the tube. This medication will break down the foam so the gas can be burped.

Although it is best to treat bloat early, there are situations where bloated cattle are found when they are close to death. The signs of impending death from bloat include rapid breathing, depressed attitude and a heavily distended abdomen, with the left side of the abdomen distended to or over the level of the spine. In cases like these, there may not be time to pass a stomach tube. The best emergency treatment at this point is to stick the upper left flank with a sharp knife to let the gas out quickly. This should only be done in the upper portion of the left flank and only in a situation where death is imminent. Follow up this procedure with a course of antibiotics, as the hole created can lead to infection.