TOXINOLOGY OF A BOVINE PARAPLEGIC SYNDROME

A clinical entity named 'bovine paraplegic syndrome' ('sindrome parapl ejico de los bovines') has spread alarmingly in the cattle-growing are as of the central and eastern plains of Venezuela. It is estimated tha t four million cattle are bred in the area where the disease occurs. T he mortality ranges from 5 to 25% of the animals at risk, mostly pregn ant or lactating cows. The principal characteristic of the bovine para plegic syndrome is ventral or sternal decubitus, in animals that make vain efforts to stand when stimulated. The diagnosis is established wh en all other possible causes (e.g. paralytic rabies, botulism and bloo d parasites such as Anaplasma marginal, Babesia bovis, B. bigemina, an d Trypanosoma vivax) have been ruled out clinically and by laboratory tests. Death always occurs, usually after a few days, and there is no known treatment. In this work, we describe results that show the prese nce of a toxin in the cattle suffering from, or liable to suffer from the syndrome. The toxin is produced by ruminal bacteria. In squid gian t axons under voltage clamp conditions, the toxin blocks the sodium cu rrent. We detected the toxin analytically by absorbance measurements a t 340 nm after reacting with picrylsulfonic acid. We obtained a good s eparation of the toxin with isocratic high pressure liquid chromatogra phy, using 40% methanol in water on phenylborasil columns.