Hemorrhagic bowel syndrome can be devastating, even in apparently healthy herds. The disease has a fatality rate of at least 85%, as treatment is rarely successful. This makes prevention key in dealing with HBS.
"Just about every animal I've diagnosed has died," says Dr. Ahren LaFollette, of Edgerton, Minn. "It makes economic sense for producers to prevent this disease, as an affected cow is usually a dead cow."
HBS begins with sudden and sometimes massive hemorrhage into the small intestine. No single cause has been identified, although Clostridium perfringens Type A may contribute. Mold and early lactation rations rich in energy and protein but low in fiber are also possible culprits.
"HBS is a relatively new disease, so many dairies may not even be aware of it," says Kim Anderson, DVM, professional services veterinarian for Novartis Animal Health US, Inc. "Unless a postmortem is done, it can easily go undetected."
LaFollette makes the following recommendations for preventing HBS:
- When a cow dies of unknown causes, conduct a postmortem examination.
- Avoid overcrowding and frequent mixing of animals to minimize stress.
- Make sure the ration contains adequate long-stem forages and no mold.
- Vaccinate for Clostridium perfringens Type A.