Here, you can find current information on some of the parasitic problems in the tropics, using examples from Colombia (South America).  The section is divided in four videos distributed in three modules that cover: a) the biology of parasites in ruminants, 2) mechanisms of resistance, 3) examples of resistant cases in Colombia, and 4) integrated management practices.  The first video provides some background information on the biology of parasites that is critical to understand methods to combat parasite infections/infestations, whenever they pose a threat.  The 2nd and 3rd videos explain why our "modern" production and management practices have led to problems of parasite resistance and what are the various mechanisms of resistance at the molelular level.  The final video proposes solutions to overcome the problems of resistance and achieve more sustainable production systems to raise livestock.   Because of widespread parasite resistance to most existing chemicals, the era of easy parasite control is over.  "Modern" production systems tend to speed up resistance problems to the point of making some farms no longer economically profitable.