Características micrográficas y digestión ruminal in vitro de una planta tóxica (Nerium oleander, "laurel de campo") versus otra inocua (Eucalyptus camaldulensis)

Abstract

Poisonous plants are a serious threat to cattle. When eaten by animals in natural conditions, they lead to diverse organ injuries and may cause death. Plant poisonings are common and take place mostly during the dry season, when forage lacks due to scarce raining. Cardiotonic glycosides are compounds present in some groups of plants with marked pharmacological effects on the digestive system as well as the heart. "Laurel de campo", "laurel rosa" or "oleander" is a widespread shrub in many countries that may cause death if ingested. Veterinarians often confuse the plant material found in the ruminal content after a necropsy with the non-toxic plant "eucalyptus". The purposes of this work are to describe some botanical characteristics of both plants to allow the differentiation between the leaves of "oleander" and "eucalyptus", as well as to investigate the artificial ruminal digestion of both plants by means of the miniature artificial rumen. Leaves of N. oleander and E. camaldulensis were submitted to artificial ruminal digestion and later microhistological analysis to determine the effects of ruminal microorganisms on plant structures. No significative changes were observed for the considered vegetal organs. We conclude that microhistological analysis is a useful tool for the complementary diagnosis to confirm plant poisonings, allowing in this particular case the differentiation between Nerium oleander, extremely poisonous, and Eucalyptus camaldulensis, non-toxic species.