Tratamientos médicos para inhibir el comportamiento sexual en sementales

espanolCon frecuencia en la practica clinica los propietarios y jinetes solicitan tratamientos medicos que permitan inhibir el comportamiento sexual de los sementales fuera del ambito reproductivo, particularmente en el entorno de entrenamiento o competicion, sin que se pierda de forma permanente su capacidad reproductiva. En el mercado existen diferentes tratamientos hormonales alternativos a la castracion quirurgica pero cuya efectividad, reversibilidad o efectos secundarios pueden limitar su uso. Tradicionalmente se han utilizado los tratamientos continuos a base de progestagenos y actualmente estan cada vez tomando mas relevancia las vacunas anti GnRH por su comodidad de administracion. Sin embargo, en ambos casos se debe tener en cuenta el futuro uso de esos caballos como sementales ya que su reversibilidad, especialmenteal usarse de forma prolongada en animales jovenes, no esta totalmente asegurada. Otros tratamientos, como el uso de antagonistas y agonistas GnRH presentan limitaciones por la variabilidad de resultados esperables con ellos, ademas de por su alto coste. A nivel clinico es relativamente frecuente la utilizacion de farmacos tranquilizantes relajantes o ansioliticos con este objetivo, sin embargo, es importante mencionar que su uso es cuanto menos cuestionable porlos posibles efectos adversos que pueden ocasionar. En este articulo hacemos una revision de los tratamientos medicos que con mas frecuencia se usan en la clinica para controlar el comportamiento sexual de los caballos, destacando las publicaciones mas relevantes, con el fin de exponer su efectividad, las complicaciones mas frecuentes,la reversibilidad esperable en cada caso y las restricciones de uso que puedan existir. EnglishIn clinical practice, owners and riders frequently asked for medical treatments to suppress stallion’s sexual behaviour outside of a breeding environment, particularly in training or competition, without permanently losing their reproductive capacity. There are different hormonal treatments on the market that can be used as alternatives to surgical castration, but whose effectiveness, reversibility or side effects may limit their use. Traditionally, continuous progestogen-based treatments have been used, and anti-GnRH vaccines are now becoming more popular due to their more comfortable administration guideline. However, in both cases the subsequent breeding career of these horses must be taken into accountsince their reversibility, especially when used for long periods of time in young animals, is not currently fully assured. The use of GnRH antagonists and agonists have limitations due to the variability of results or/and their high cost. Furthermore, in practice, the use of relaxing or anxiolytic tranquilizers is relatively frequent for this purpose, however,either side-effects or absence of efficacy studies makes their use questionable or contraindicated. In any case, it should be noted that behavioral problems must be evaluated globally and that when choosing a pharmacological agent, possible side effects, as well as national regulations regarding registration for its use in this species and further rules regarding sport horses or “food-producing” animals must be taken into account. This article reviews the major pharmacological agents reported to control sexual behavior in stallions and outlines the most relevant papers, their efficacy, side effects, expected reversibility and possible regulations regarding food-producing and competing animals.