In Colombia the rearing of hair sheep and goats are expanding in various regions for being an alternative for meat and milk production at competitive prices due to their adaptability and easiness to digest rough fodder. Among the ectoparasites that affect small ruminants traditionally are recognized the lice and the sheep keds Melophagus ovinus (Díptera: Hippoboscidae), however fleas are not included. Here the occurrence of the common cat flea Ctenocephalides felis felis (Díptera: Siphonaptera) affecting sheep and goats in a farm at the Sabana de Bogotá are described an so there was performed an epidemiological and parasitological evaluation. The barn maintained animals in rotational grazing at an approximated stocking rate of 25 head/ha, receiving additional supplements of hay and silage. The presence of the flea was confirmed in sheep and goats, young and adult, as well as in dogs. Diverse degrees of anemia were evidenced but the association between flea infestation and anemia, or the presence of other anemia producing agents could not be studied. In the farm synthetic parasiticides are not used, extracts of Ruda (Ruta graveolens) are administered to mitigate parasitosis, without major efficacy. Sheep and goat breeders in the tropics should consider flea infestation as an agent causing adverse animal welfare situations in their farms. Control should start from the knowledge of the life cycle of the flea, trying to interrupt it.

En este artículo se realiza una breve revisión acerca de la epidemiología y causas de la muerte súbita de los bovinos mantenidos en condiciones de pastoreo en América Tropical. Se define la muerte súbita como la condición donde los animales aparecen muertos de forma repentina o bien poseen una enfermedad de muy corto curso; situación bajo la cual no se da tiempo para el desarrollo de lesiones patológicas, dificultando el diagnóstico, el cual debe basarse en la recolección de evidencia epidemiológica. Se destaca como factor predisponente para estas patologías, a las condiciones edafológicas de las sabanas tropicales, principalmente en lo que refiere a las limitaciones nutricionales y de balance mineral de animales y plantas. Dentro de un listado de posibles agentes etiológicos asociados con este tipo de cuadro clínico en rumiantes en pastoreo, se discute el conocimiento epidemiológico y las herramientas diagnósticas a las que se debe recurrir para aclarar la etiología y naturaleza de la situación de mortalidad que afrentan nuestros ganaderos.Palabras clave: bovinos, diagnósticos, epidemiología, etiología, mortalidad.

The reconversion of illicit crops implies using alternative production systems. The Integrated Sustainable Agriculture and Livestock Nuclei (NISA) project supported these processes. A NISA nucleus consists of 20 to 28 producers who share knowledge of livestock innovation. A previous exercise in participatory epidemiology allowed to identify the most sensitive problems, including parasitic diseases. A transversal epidemiological study was performed in young bovines of different ages to establish parasitic infection dynamics in NISA nuclei in the municipalities of Puerto Rico and La Macarena, as a basis for prevention and control interventions. Ten young cattle and some adult animals were sampled in each farm for hematological and coprological analysis the weight and condition of each animal were recorded. Weight gain in calves fluctuated between 450 and 500 g/d. Internal parasites were found on all farms, but they were different in importance <em>Strongyloides papillosus</em> and <em>Toxocara vitulorum</em> presented high counts in cattle from 2 to 5 months of age. Trichostrongylids reached peak of excretion at six months of age. Moderate concentrations of parasites induce immunity thus, anthelmintic treatment is recommended only at this age. The existence of endemic stability for hemoparasites was suggested. Professional counseling should be directed to ensuring that producers understand these stability processes without abusing drugs, while attending to the components of animal handling and welfare. Rural extension requires accompaniment by public policies and attention to socioeconomic aspects in order to contribute to rural development, which help to the reduction of inequalities in the Colombian countryside.

Como parte de un estudio epidemiológico longitudinal desarrollado en la Altillanura del departamento del Meta durante un año (1998-1999), y con el fin de determinar alteraciones de patología macroscópica y cambios histopatológicos asociados al Síndrome Neuroparalítico Bovino (SNB), se estudiaron 39 bovinos entre 2 y 8 años de edad, los cuales se encontraban afectados naturalmente por esta causa. Se procesaron muestras de 305 tejidos por la técnica de inclusión en parafina, para determinar las principales lesiones histopatológicas. En la necropsia los hallazgos más importantes fueron la presencia de cuerpos extraños (huesos, arcilla, piedras, madera) en el rumen y retículo; en la mayoría de los casos ocurrió compactación del librillo y vesícula biliar pletórica. La congestión de envolturas cerebrales fue una alteración común en todos los casos. Los hallazgos histopatológicos más relevantes incluyeron cambios vasculares en tejido nervioso, dados por edema, congestión, hemorragia e hiperplasia de células endoteliales; cambios grasos intracitoplasmáticos y megalocitosis en hepatocitos; en el riñón, infiltrados mononucleares en glomérulos y túbulos contorneados con vacuolización intracitoplasmática; hialinización y fragmentación de miofibrillas en músculo estriado esquelético y presencia de Sarcocystis bovis y necrosis de Zenker en músculo estriado cardiaco. Se confirma que el Botulismo bovino no produce alteraciones microscópicas de valor; las otras alteraciones son compatibles con Neurotoxicidad Retardada por Pesticidas, deficiencias energéticas y leptospirosis.Palabras clave: Botulismo, Histopatología, Neurotoxicidad, Pesticidas, Sarcocystis.

The La Macarena mountain range delimitates a transition between Andean ecosystems. There are currently important human settlements in the region that are searching for a decent living in extensive cattle raising. A project supported by the Colombian government is being conducted in the municipalities of Puerto Rico and La Macarena, which aims to introduce a technological package of tropical cattle farming in order to modernize livestock production in communities with a vulnerable population. The use of participative epidemiology tools in the framework of the project’s activities is hereby described, and particular attention is brought to the validity of using participative methods as an alternative to approach the problems of local rural producers and suggest alternative solutions in situations where resource limitations hamper the use of other study methods. Individual interviews and group workshops were carried out with livestock owners, who described the health alterations observed in their farms from their own perspective. After triangulation the description of the disease was compared with direct field observations and with the scientific descriptions of cattle health problems in the tropic. It was detected that deficiency diseases (pica, botulism) are very frequent in the region, reflecting the poor quality of soils and pastures. There are infectious calf diseases (calf scours, black scours) that occur due to management mistakes that are easily avoidable. There are also toxic and parasitic pathologies (photosensibilization and haemoparasites) that require a better understanding of their dynamics, so as to be able to design appropriate prevention strategies.

Parasites are organisms that live inside other living organisms or on them to get nutrients without providing any compensation in return. In medical and veterinary science, generally, only eukaryotes to metazoans are accepted as a “parasite”, that is, protzoa, helminths and arthropods. Some include arthropod-borne bacteria, the rickettsia. The teaching of this discipline has emphasized on the taxonomic components of organisms and has neglected aspects of understanding of the relation host-parasite, the comprehension of ecological interactions and wild cycles, co-evolution in the niches that support the possible selection of resistant animals to parasites and the arguments regarding population genetics, which allow the understanding of the problems of development of parasite resistance. This article shows teaching experiences from the Veterinary Parasitology Program, in which, although specimens in alcohol and formalin are still being used to demonstrate parasitary structures, increasingly more living organisms are being used as the basis of teaching and learning, along with information and communication technologies (ICTs) to facilitate the understanding of parasitic processes in natural tropical conditions.