Assessing the efficacy of Duddingtonia flagrans chlamydospores per gram of faeces to control Haemonchus contortus larvae.

The aims were (a) to quantify the number of Duddingtonia flagrans chlamydospores per gram of faeces (CPG) recovered from sheep administered with different oral doses and, (b) to describe the relationship between CPG and eggs per gram of faeces (EPG) on the efficacy to reduce Haemonchus contortus infective larvae. Three doses of chlamydospores per kg BW were orally administered during seven days: (T1) non treated control group, (T2) 1 x 10(6), (T3) 2.5 x 10(6) and (T4) 5 x 10(6). Three lambs, infected with H. contortus, were used per group. Faeces were obtained from the rectum of each lamb during the fungal administration period (days 0-6) and for six days after that period. Four coproculture replicates were made from each animal in days 2, 4, 6, 8 and 10. A higher chlamydospore dose produced higher CPG in faeces (p < 0.05), but a clear dose dependent effect was not found either in the larvae reduction or in the CPG:EPG ratio. When ratios were re-analyzed, independently of the treatment groups of origin, a better efficacy was obtained with a ratio from 5 to 10 CPG:EPG and a higher ratio (> 10 per egg) showed a lower reduction efficacy (p < 0.05). The binomial analysis showed that for each unit of increment in CPG:EPG ratio there was a reduction of larvae number until a point (between 5 and 10 CPG:EPG) where no further reduction was detected. The surface response test indicated that the number of larvae was reduced by CPG until possible saturation. The highest CPG:EPG ratios did not necessarily improve efficacy of D. flagrans.

Prevalencia de Dirofilaria immitis en perros callejeros de la ciudad de Mérida, Yucatán, México / Prevalence of Dirofilaria immitis in stray dogs in the city of Merida, Yucatan, Mexico

Se estudió la dirofilariasis canina en la ciudad de Mérida Yucatán, en el sureste de México, con el objetivo de determinar su prevalencia y comparar la efectividad de la prueba de gota gruesa y Knott modificada , con la presencia de parásitos adultos en la necropsia. prevaleció Dirofilaria immitis en 6.54 por ciento y Dipetalonema reconditum en 7.47 por ciento. La prueba de Knott modificada detectó 11 casos positivos a microfiliarias circulantes y la prueba de gota gruesa solamente detectó 3 casos. Se encontraron 2 casos de filariasis mixta. Cinco animales fueron positivos a parásitos adultos en la necropsia y 7 positivos a microfiliarias circulantes; sin embargo, 2 casos con parásitos adultos en la necropsia no pudieron ser detectados por la técnica de knott modificada, y 2 casos positivos a Knott modificada no presentaron parásitos adultos a la necropsia. Se presentó un promedio de 6 parásitos adultos por cada positivos; los parásitos fueron localizados en distintas partes del corazón. Se hallaron 3 casos positivos a larvas de Dipetalonema reconditum en la orina, lo que representa 5.54 por ciento de positividad. Se concluye que para el diagnóstico de la dirofilariasis canina es necesario la detección de microfilarias en sangre y acompañarse de pruebas complementarias