Verminosis is one of the oldest diseases known to man; however, no tools have yet been found for its effective control, because when only anthelmintics were used to control it, it was discovered that these parasites found mechanisms of resistance to the various drugs launched on the market, as well as transmitting these characteristics to their offspring. Nowadays, worms are the main disease of small ruminants, especially in tropical climates, where their larvae find ideal conditions for their full development. Therefore, it is necessary to know within the herd which animals are highly susceptible, which are resilient and which are resistant, and to do this we use tools such as: selective and strategic treatment, always accompanied by tests such as: O.P.G., mean globular volume, O.P.G. count reduction test, adequate nutrition, pasture management, among others. In other words, there is no single measure, but rather a set of measures that are always aimed at reducing pasture contamination without any loss in the productivity of individuals.