The purpose of the present work was the anatomical, histological and histochemical description of Rhamdia quelen juvenile digestive system. Samples of gut were fixed, dehydrated and included in paraffin and then stained with haematoxylin and eosin. For the identification and differentiation of mucosubstances the preparations were treated with Periodic Acid Schiff, Alcian Blue pH 0,4 and 2,5 and PAS/AB pH 2,5. Anatomical details of the oesophagus were like a short tube with primary and secondary mucous folds. The stratified epithelium is composed of three cellular types: small cells, abundant goblet cells with acid and neutral mucosubstances (MS) and large acid cells. The stomach is J-shaped and its mucosa presents broad and deep folds in relaxing state. Histologically, the stomach shows three different regions: cardiac, fundic and pyloric region. The luminal surface of the epithelium consists of a layer of secretory columnar cells of neutral MS. Tubuloacinar glands were surrounded by connective and muscular smooth fibers bundle. The intestine extends from the stomach until the anus, and four different sections can be distinguished: ascending, descending, convoluta and terminal straight. It was identified a simple columnar epithelium mainly composed by two cellular types: absorptive cell and goblet cell neutral MS secretory. On the basis of the anatomical and histological study carried out, we conclude that R. quelen presents an alimentary canal compatible with species that possess omnivorous nutritious habits.

<p>Durante los meses de febrero a octubre de los años 2014 a 2016 se investigó el padecimiento de leishmaniosis visceral en caninos atendidos en la Facultad de Ciencias Veterinarias de Corrientes, Argentina. El estudio se efectuó a través del método indirecto (detección de anticuerpos contra el antígeno rK39 en suero de sangre venosa) y la prueba directa (extracción de medula ósea por punción en distal de costillas y observación microscópica de amastigotes). Durante los 3 años se examinaron un total de 409 pacientes. En 2014 (89 muestras) se registraron 22 casos positivos (24,7%); en 2015 (164 muestras) se detectaron 39 casos positivos (23,7%) y en 2016 (156 muestras) se revelaron 56 pacientes positivos (35,8%). En todos los casos los caninos fueron positivos a ambos métodos diagnósticos. En el total de años estudiados, la prevalencia en caninos fue de 28,06%. Se enfatiza que ante los pacientes sospechosos de padecer leishmaniosis visceral, se efectúen conjuntamente los métodos diagnósticos serológico (indirecto) y parasitológico (directo).</p>