ACUTE DEATH IN DAIRY COWS

Dairy herds are reporting sporadic acute death losses among their dairy cows. The symptoms of the disease are: 1) sudden onset 2) severely depressed and weak 3) looks like endotoxic shock 4) some cows have a bloody diarrhea and 5) death occurs 12 to 36 hours after the onset of symptoms.

The primary diagnosis made by diagnostic labs is Clostridium perfringens Type A. Postmortem signs are generally limited to a hemmorragic enteritis in the small intestines and occasionally in the large intestine. Sometimes large blood clots are present in the intestine.

I believe that most diagnostic labs say that this problem is causes by Clostridium perfringens type A because it does not produce one of the other specific toxins for Clostridium. The common Clostridium vaccines that are on the market do not protect against type A,.

AABP discussion group often debates this disease. There are several labs that make autogenous vaccines from isolates of Clostridium perfringens type A. However, there is very little proof that these autogenous vaccines provide protection. Veterinarians are not sure if they should recommend autogenous vaccines. Recently several veterinarians have isolated Clostridium perfringens type A from normal healthy cows.

I recently saw two cows die of this syndrome within 12 hours of each other. These cows appear to be the most aggressive eaters in the herd and the biggest and best cows. They often get sick before or soon after calving. I think putting these cows on the close up diet is a contributing factor. Perhaps cows that sort their TMR are more susceptible to this disease. This disease reminds me of overeating in sheep. When we first see these cows they are so sick they can not stand up. Extensive fluid therapy generally is not successful. I have not tried autogenous vaccines. I believe that first calf heifers are more susceptible than older cows. I think that overeating may be the primary factor involved in this disease.

This is another example of veterinarians being asked to make recommendations when we do not have satisfactory scientific information. That is why this is a "not" topic on AABP Internet discussion group.