| Abstrakt: |
Twenty-two lactating Holstein cattle in Tennessee had clinical signs of intoxication with preformed Clostridium botulinumtoxin. These signs included weakness, paralysis of the tongue and chest muscles, abdominal breathing, and, in 11 of the 22 cows, death. Differential diagnoses included hypocalcemia, hypo-magnesemia, carbohydrate overload, and several toxicoses including mycotoxin, lead, nitrate, organophosphate, atropine or atropine-like alkaloid, and botulism. A diagnosis of botulism by the ingestion of preformed C. botulinumtype B toxin was made by eliminating these other diseases, by finding C. botulinumtype B spores in 3 bales of round bale barley haylage fed to these cattle, and by isolating preformed type B toxin from 1 of the 3 bales. Confirmation of the toxin type was made by demonstrating mouse lethality by intraperitoneal injection of specimen extracts with neutralization by C. botulinumtype B antitoxin. The haylage, harvested green and encased in black plastic bags to facilitate fermentation, was presumably contaminated by the botu-linum toxin when fermentation failed to produce enough acid to lower the pH to 4.5, the pH below which C. botulinumgrowth is inhibited. Farmers and ranchers who use round hay balers to produce haylage should be alert to this potential problem. |
