Bloody Gut / Hemorrhagic Bowel
Dr. Clell V. Bagley, D.V.M.
USU Extension Veterinarian
A disease called Bloody Gut or Hemorrhagic Bowel has been seen much more often in recent years all across the U.S., including Utah. Producers need to be aware of it and take measures to prevent it if diagnosed in their dairy operation. It is most often associated with total mixed ration (TMR) feeding, but not exclusively so.
Hemorrhagic Bowel affects adult dairy cattle at all stages of lactation, and may appear with one of several different signs. These signs range from not doing well, to downer cow, to bloody diarrhea, to very sudden death. The one consistent finding is that at necropsy there is a hemorrhagic intestine with a section filled with bloody fluid, or even a large blood clot. Because of the variety of signs, if dead cows are not necropsied, the dairyman may not be aware this problem is occurring on his dairy.
The exact cause has not yet been determined, but the accumulating information indicates that it is due to a combination of factors and not just one agent. When high levels of grain are being fed, too much of it reaches the intestine too quickly. This in turn allows the bacteria Clostridium perfringens type A, which is normally present, to grow rapidly and produce a toxin. The grain load may also reduce gut motility and aid in providing the ideal environment for the bacteria to grow. The toxin produced then affects the animal, and the signs shown depend on the rate of production, absorption, etc., of the toxin. The presence of this bacteria may or may not be part of the development of the disease; that remains to be determined, but it appears that it is most likely involved. This disease development process is very similar to that for enterotoxemia or overeating disease. The Clostridium perfringens Type A is closely related to the Clostridium perfringens Types C and D which cause enterotoxemia.
Other events may also contribute to the development of this disease. Haylage has been implicated, especially if it is of poor quality. On some affected dairies, high numbers of clostridial organisms have been present in this type of silage. Even grass silage, along with feeding high rates of grain has been implicated. The feeding of corn silage within a very short time after ensiling (one week) has also been implicated in some herds. The physical form of the grains may also be a factor with the fine ground type passing through the digestive tract more quickly than those that are rolled or flaked.
As this disease has been investigated, it has become more apparent that individual cows are able to select their own diet by sorting and feed selection. They are much better at it than we had previously realized. This selection ability allows individual cows to select specific feeds from the ration, and can result in individual acidosis. Rations high in grains increase the likelihood of sorting, and thus cow susceptibility to Hemorrhagic Bowel syndrome.
Treatment of cows affected with this syndrome has not been very successful, partly because it progresses so rapidly. Some cows have recovered after heavy, early doses of antibiotic. The use of Clostridium perfringens antitoxin may be of some help. The use of large volumes of kaolin and pectin products orally may also be of benefit. A few cows have responded to early abdominal surgery, which permitted intestinal massage, along with the use of antibiotics, IV fluids and intestinal cathartics. Still another few cows have survived after surgical resection of the affected portion and rejoining of the healthy intestine.
Prevention is the key to at least reducing the numbers affected. The critical control points for prevention are to increase the forage and the forage NDF, while at the same time decreasing grain intake. This does tend to reduce milk production slightly, but that has been a positive trade-off for some affected dairies. The guidelines most commonly recommended currently are for a minimum of 40% forage in the ration and for at least 20 to 22% of the NDF to come from forage. If the forage NDF drops below 20%, the problem seems to re-appear. If the dairyman and nutritionist feel the ration eaten is within these guidelines, then other factors should be investigated. These include the feeding of haylage (especially lesser quality or contaminated with soil / clostridia), the physical form of the ration which allows easier sorting, high grain corn silage, high moisture corn and readily fermented small grains. Cow discomfort or lack of stall space may be factors that encourage �slug feeding� of some cows. If feed is mixed and then allowed to sit in the feed wagon for several hours before being fed, it may allow an increase in the number of clostridial organisms present. Any potential problems like these should be identified and corrected.
The routine use of a forage particle separator will allow monitoring for physical fiber and feed consistency along the bunk, as well as sorting. More frequent feed push-up may reduce problems with sorting.
Vaccines have been used with very mixed results. Some producers have just increased the frequency of use for the seven-or-eight-way clostridial vaccines they had already been using. Others have added booster doses every 4 months of Clostridium perfringens type C & D. Others who have had the Clostridium perfringens type A organism isolated from cows that died on their dairy have had an autogenous vaccine prepared and used it. Again, each of these vaccines have seemed to help in some herds, but have not in other herds. These clostridial organisms are all closely related. However, it still remains to be determined which specific toxin is involved and how to produce a vaccine that will stimulate a strong level of immunity against that specific toxin. Until then, prevention will come primarily through management of the ration.