Pet Columns, Office of Public Engagement, College of Veterinary Medicine at the University of Illinois at Urbana-Champaign

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Belching Keeps Four Stomachs Bloat-Free


Pet Column for the week of March 5, 2001


Office of Public Engagement
2001 S. Lincoln Ave.
Urbana, Illinois 61802
Phone: 217/333-2907
By Carrie Gustavson
Information Specialist

By nature of how their stomachs work, cattle are pigs! They burp every couple of minutes in order to relieve the gas that builds up in their stomach. Cattle, or any other "four-stomached" animals such as sheep, goats, and even llamas, have one "stomach" that is actually a large fermentation chamber called a rumen. If gas gets trapped, the rumen can balloon out with so much force that the animal can't even breath. It's an emergency. If you see cattle all puffed up with bloat, call a veterinarian for help right away.

Beans anyone? Legumes, it seems, cause problems whether you have one stomach or four. "When eaten by cattle or any ruminant, lush rapidly growing legumes, such as alfalfa and some clovers and winter wheat produce a gas-trapping froth," says Dr. Dawn Morin, large animal veterinarian at the University of Illinois Veterinary Teaching Hospital in Urbana. "When the gas bubbles become trapped in the rumen, bloat results."

The rumen is full of helpful microbes that are able to break down the plants that cows and other ruminants eat. All that activity produces a lot of gas-up to 2 liters a minute-which is why cows have to burp so much. When gas in the rumen is trapped in froth, it is just like it is in the foamy head of a beer. This type of bloat, termed "frothy" bloat, is most likely to occur in animals on clover or alfalfa pasture, or those fed high-grain diets.

Bloat might also occur if something blocks the passage to the stomach, or esophagus, so that the animal can't eructate -- a fancy word that means "burp."

"Esophageal obstruction, or choke, is frequently caused by the ingestion of a hedge apple, potato, sugar beet, turnip, corn cob, or other foreign object. Enlarged lymph nodes or abscesses can also block the esophagus," says Dr. Morin.

The rumen is on the left side of the body, so a distended rumen will be more apparent on that side. But if it's really distended, there will be a bulge on the right side as well. "If untreated, the animal may have trouble breathing, may stagger, and may die," says Dr. Morin.

A veterinarian will try to pass a stomach tube to determine whether the problem is frothy bloat or caused by choke, and treat it accordingly.

"Bloat can occur so quickly that it may catch an owner off guard. Sometimes owners will try to relieve severe bloat by puncturing the rumen with a knife as a last resort," says Dr, Morin. "That might allow the animal to survive the bloat, but unfortunately, a deadly infection is a likely result."

Products containing medication to prevent frothy bloat are available commercially as licks, topdress, or feed additive. Otherwise, bloat can be minimized by avoiding high-risk pastures, limiting time spent grazing, feeding hay prior to grazing, spraying pastures with oils, applying oil to the animals' flanks (they will lick it), or daily oil drenching.

"A few animals should be turned out on suspect pastures before the whole herd to determine the pasture's 'bloat potential,' so as to avoid a high death loss when large numbers of animals are affected," says Dr. Morin.

For more information on how to prevent bloat, contact your local large animal veterinarian.