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The objective of the present study was to evaluate the efficacy of Metarhizium anisopliae on the control of Rhipicephalus microplus in cattle infested naturally in the Mexican tropics. The study was carried out on a ranch in the Mexican tropics. Base on the number of adult and immature (larvae and nymphs) R. microplus ticks 20 steers were assigned into two groups of 10 cattle. Animals in the treated group (average of 73.4 y 27.5 adult and immature ticks respectively) were sprayed with a mixture of Ma14+Ma34 of M. anisopliae at a concentration of 1x108 conidios/ml. The other group remained as untreated control (average of 77.7 y 24.7 adult and immature ticks respectively) and treated with water+Tween 80. Each group received 4 applications every 14 days. Adult and immature stages of ticks were recorded on days 0, 3, 5, 7 and 14 post-treatment. From the first application treatment to the end of the experiment, animals in the treated group had lower counts (P < 0.05) of adult (30.9-87%) and immature (35.8-72%) ticks. The results demonstrate the efficacy of repeated treatment with the strains Ma14+Ma34 of M. anisopliae can be used as an alternative to control natural infestation of R. microplus on cattle in the Mexican tropics.

The aim of the study was to determine the presence of antibodies against Neospora caninum and its DNA in blood samples from bovine females from the northern region of the state of Veracruz, Mexico. A cross-sectional epidemiological study was carried out in 13 municipalities, with a sample size of 821 animals. Blood and serum samples were analyzed through ELISA and PCR, respectively. Overall prevalence was 20.8 %; the highest specific prevalences were obtained in breeding cows (27.4 %), crossbred cows (20.9 %), second-calving cows (23.2 %), three year-old cows (20.6 %) and cows with abortion history (20 %). The risk factors associated with seropositivity were dairy cattle (OR = 1.9; IC95 %: 1.1-3.4) and dog presence in the farms (OR = 5.3; IC95 %: 1.3-22.3). The presence of N. caninum DNA was demonstrated in 4 out of 12 blood samples tested, which evidenced the existence of active infection. In conclusion, there were risk factors associated with bovine neosporosis, which proved the existence of active infection by N. caninum in cows from the state of Veracruz, Mexico.