Plant poisoning in stock and the development of tolerance

Abstract

From the results of experiments conducted upon thirty-two rabbits it appears (a) that the continuous ingestion of leaves or underground stems of gifblaar does not induce the development of tolerance to this plant; and (b) that the active principle of gifblaar has cumulative effects, that is, it is inactivated in the body or excreted at a very slow rate. It is also possible that repeated small doses of the plant may cause progressive damage to organs of vital importance (heart) and that the sum total of these consecutive and progressive lesions is sufficient to cause death in spite of the fact that the active principle has been partly or completely excreted. There also was a certain amount of evidence that some animals became sensitized to the effects of the plant, unless we accept that these animals possessed an idiosyncrasy to gifblaar.