Sudden death often result of puzzling bowel disease

Cause still mystery 

Hemorrhagic bowel syndrome, also known as jejunal hemorrhagic syndrome and clostridial enteritis, is most commonly seen in mature dairy cows and generally causes sudden death.

It is a recently recognized ailment.

Cows that are diagnosed early often have gut pain, are weak from blood loss or pass blood-stained manure. 

Veterinarians don’t know the exact cause of the disease, but one of the clostridial organisms — clostridium perfringens Type A — is often isolated from the site and the blood. 

Clostridial may ring a bell with many producers because it is the family of diseases that are targeted by the multivalent clostridial disease bacterins, which are the seven-way, eight-way and nine-way “blackleg” shots. 

However, Type A is not in any of the vaccines. Veterinarians may keep prescribing these vaccines, but I don’t think there is much cross protection to this type of clostridial. 

Still, it is a wise decision to vaccinate because many other types of clostridial diseases can crop up, such as tetanus, redwater, clostridial enteritis, malignant edema and of course the most widely known, blackleg. 

HBS was an almost unknown disease until 1999 when veterinarians started discovering cows that had died from huge blood clots, usually in portions of the small intestines.

Those that lived longer would get the blood clotting in the small intestines, where it would cause a blockage. The abdominal pain occurs when the small intestines are stretched. 

Veterinarians will often find distended loops of bowel when doing a rectal exam and they also may find blood mixed with the manure.


Corrective surgery can remove the blood clot if the diagnosis is made early enough, and in most cases a portion of the intestinal tract has to be removed. 

The surgery is complex and has a place only in top end dairy cattle or purebred beef cattle. Unfortunately, the prognosis is still low for survival, even with this surgery. 

The disease is usually seen in top end dairy cows in their third or so lactation but has also been reported in heifers. 

It has also been diagnosed recently in beef cows and even a breeding bull. 

Most recently, it was found in a few nine-month-old male beef calves with the same sudden death and post mortem findings. 

With such a high fatality rate on valuable animals, it’s understandable why producers are concerned.

It is called a syndrome now because high carbohydrate diets and the aspergillus mould are thought to cause it along with the Type A clostridial. 

The fungus aspergillus could create a lesion or ulcer-like condition in the intestine, causing it to bleed, or it could reduce the cow’s immune system, leading to the cascade of problems that results in hemorrhagic bowel syndrome. 

Researchers have tried infecting cattle with only clostridium perfringens A and couldn’t cause the disease. They are now working to determine the other significant pieces to the puzzle. 


The disease is sporadic, despite having a high death rate. It shows up as a sudden death here and there, and if deaths occur on the same farm they are often months apart.

Producers manage it by watching their cows’ stress level and providing good balanced rations. Veterinarians advise the multivalent clostridial vaccines. 

Broader protection is best because of the potential for cross protection similar to what occurs with some of the other clostridial perfringens-type organisms, such as Type B being cross protected from giving types C and D.

It is difficult to know if current vaccinations reduce the disease because it has such a low incidence. This is especially the case because none of the clostridials on the market in Canada carry the clostridium perfringens Type A. 

We may break the chain in the future and hopefully reduce the incidence if a vaccine does come on the market and we can eliminate one of the potential causes of this disease complex.

Producers should always have any sudden death necropsied by a veterinarian because clostridial causes can be determined most times. 

Be aware of new discoveries on the multifaceted cause of HBS and follow your veterinarian’s suggested vaccination plan for your herd. 

Veterinarians know the disease prevalence in your area and what combination of vaccines will give the best protection.

Buying lots of vaccine is cheaper than losing a cow or calf to a type of clostridial disease.


HBS is sporadic but other clostridial diseases can cause outbreaks in non-vaccinated animals. It is always best to prevent disease with vaccination than treat it.

Roy Lewis has a veterinary practice in Westlock, Alta. and works part time as a technical services veterinarian with Merck Animal Health.

  • If GMO seeds are so safe for consumption, why are more and more people and livestock(in this case dairy cattle) developing gastrointestinal issues and bowel syndromes?

  • Bill

    In the article it says directly, “It is called a syndrome now because high carbohydrate diets and the aspergillus mould are thought to cause it along with the Type A clostridial.` Aspergillus mold has been especially prevelant these past few years due to extreme weather conditions across the continent.

    If you have any sort of scientific study regarding increased gastrointestinal issues in any living creature (scientific studies) then please post it. Otherwise you are spreading hearsay without means to support your accusations.

  • I gather you didn’t notice that I was NOT making a statement, but rather asking a puzzling question. Since this syndrome has become increasingly problematic in the last decade it makes one wonder why? And now there are plans to introduce a new genetically modified Roundup Ready alfalfa to the mix? Let’s add another piece to the already complicated puzzle.