Delayed reduction of Anaplasma marginale parasitemia and packed cell volume normalization despite prolonged enrofloxacin treatment of cattle co-infected with Trypanosoma vivax.

Although co-infections of Trypanosoma vivax, Anaplasma spp., and Babesia spp. have been reported, knowledge gaps remain that need to be addressed. The present study evaluated the efficacy of enrofloxacin (7.5 mg/kg) against A. marginale in naturally infected cattle and cattle experimentally co-infected with T. vivax by observation of the variation in A. marginale parasitemia and packed cell volume (PCV) for 39 days. Bovines were distributed into two groups, each with six calves: T01 = animals immunosuppressed with dexamethasone and with latent anaplasmosis; T02 = animals immunosuppressed with dexamethasone, with latent anaplasmosis and experimentally co-infected with T. vivax on day 0 (D0). Animals of both groups were immunosuppressed with dexamethasone and received enrofloxacin (7.5 mg/kg) whenever mean values of parasitemia for A. marginale were ≥ 5% per group. Cattle of group T02 were also treated with isometamidium chloride (0.5 mg/kg) on D25. On D17 and D22 to D28 of the study, there was a higher (P ≤ 0.05) A. marginale parasitemia in animals of T02 than in those of T01. Animals of T01 required one enrofloxacin treatment to decrease A. marginale parasitemia, while those from T02 needed five treatments. From D5 to D37 of study, the mean values of PCV for calves from T02 were lower (P ≤ 0.05) than that for calves from T01. In conclusion, bovines co-infected T. vivax needed four more treatments with enrofloxacin to reduce A. marginale parasitemia and keep PCV values within reference standards.

In vivo effect of diflubenzuron, administered via mineral salt supplementation, against Haematobia irritans and Rhipicephalus microplus parasitizing cattle.

This study involved two field trials with the aim of evaluating the efficacy of diflubenzuron, via mineral supplementation, against Haematobia irritans parasitizing cattle. Concomitantly with the main trial, a stall test was conducted to ascertain the effects of a different formulation with the same active ingredient against Rhipicephalus microplus, along with the action of diflubenzuron on the reproductive parameters of R. microplusfemales that had naturally detached from cattle. Against H. irritans, it was observed that the efficacy indexes fordiflubenzuron were low (≤ 31.3% or 44.6%) or null (0.0%) throughout the study. The anti- R. microplus efficacy of diflubenzuron, at weekly intervals, ranged from 0.0 to 13.7% over the entire experimental period. Null efficacy (0.0%) was registered for diflubenzuron in relation to the reproductive parameters of R. microplusfemales that had naturally detached from cattle. The different diflubenzuron formulations, administered via mineral salt supplementation, did not show satisfactory efficacy indexes against H. irritans and R. microplus parasitizing cattle, within the experimental design of the present study. In addition, this agent did not present any deleterious effects on the reproductive parameters of R. microplus females.

In vivo effect of diflubenzuron, administered via mineral salt supplementation, against Haematobia irritans and Rhipicephalus microplus parasitizing cattle / Efeito in vivo do diflubenzuron, administrado via sal mineral, contra Haematobia irritans e Rhipicephalus microplus parasitando bovinos

Abstract This study involved two field trials with the aim of evaluating the efficacy of diflubenzuron, via mineral supplementation, against Haematobia irritans parasitizing cattle. Concomitantly with the main trial, a stall test was conducted to ascertain the effects of a different formulation with the same active ingredient against Rhipicephalus microplus, along with the action of diflubenzuron on the reproductive parameters of R. microplusfemales that had naturally detached from cattle. Against H. irritans, it was observed that the efficacy indexes fordiflubenzuron were low (≤ 31.3% or 44.6%) or null (0.0%) throughout the study. The anti- R. microplus efficacy of diflubenzuron, at weekly intervals, ranged from 0.0 to 13.7% over the entire experimental period. Null efficacy (0.0%) was registered for diflubenzuron in relation to the reproductive parameters of R. microplusfemales that had naturally detached from cattle. The different diflubenzuron formulations, administered via mineral salt supplementation, did not show satisfactory efficacy indexes against H. irritans and R. microplus parasitizing cattle, within the experimental design of the present study. In addition, this agent did not present any deleterious effects on the reproductive parameters of R. microplus females.

Resumo O objetivo deste estudo foi avaliar a eficácia do diflubenzuron, administrado via suplementação mineral, contra Haematobia irritans parasitando bovinos, em dois testes à campo. Concomitantemente, foi realizado testes em estábulo para determinar os efeitos de uma formulação diferente, com o mesmo princípio ativo, contra Rhipicephalus microplus , bem como a ação do diflubenzuron nos parâmetros reprodutivos de fêmeas de R. microplus recolhidas após desprendimento natural do hospedeiro bovino. Contra H. irritans, foi observado que foram baixos (≤ 31,3% ou 44,6%) ou nulos (0,0%) os índices de eficácia do diflubenzuron. A eficácia anti-R. microplus do diflubenzuron, observada em intervalos semanais, variaram de 0,0% a 13,7% durante todo o período experimental. Com relação aos parâmetros reprodutivos das fêmeas de R. microplus recolhidas, foi observada eficácia nula (0,0%) para o diflubenzuron. Conclui-se que as diferentes formulações administradas via sal mineral no atual estudo, contra H. irritans e R. microplus parasitando bovinos, não apresentaram eficácia satisfatória. Este agente também não mostrou efeito deletério sobre os parâmetros reprodutivos de fêmeas de R. microplus.

Historic of therapeutic efficacy of albendazol sulphoxide administered in different routes, dosages and treatment schemes, against Taenia saginata cysticercus in cattle experimentally infected.

The present study aimed to notify the history of albendazole sulphoxide (ALB-SO) and albendazole (ALBZ) efficacy against Taenia saginata cysticercus (Cysticercus bovis) parasitizing experimentally infected bovines. A total of 11 efficacy trials were performed between the years of 2002 and 2010. In order to perform these trials, animals were individually inoculated with 2×10(4) eggs of T. saginata in each study's day zero (D0). For every trial, a positive control group (untreated infected animals) and a negative control group (animals that were neither infected nor treated) were used. ALB-SO or ALB were administered in the different dosages, in different days of treatments. In a last study with this formulation, this active principle was administered orally, mixed with the mineral supplement, on the 60th DPI, in a dosage of 30mg/kg. In all trials, on the 100th DPI, all animals were euthanized and submitted to the sequenced slicing of 26 anatomical segments (fragments of approximately five millimeters) for the survey of T. saginata cysticercus. With the obtained results it is possible to verify that in the first trials, conducted in 2002, ALB-SO reached, independently of dosage and treatment scheme, efficacies superior to 98% (arithmetic means). The trials conducted in 2005 (2.5mg/kg on the 30th, 60th, and 90th DPI) obtained values of efficacy all inferior to 60%. In 2008, the trials with 2.5 and 7.7mg/kg demonstrated efficacy values inferior to 40%, for both dosages and treatment schemes (30th/60th/90th DPI and 60th DPI). When this formulation was administered orally on the dosage of 30mg/kg on the 60th DPI, the efficacy against T. saginata cysticercus reached 88.28%. ALB administered orally showed efficacy values of 0.0%, 29.88% and 28.64% in the dosages of 5, 10 and 15mg/kg, respectively, using the treatment schemes described above for each dosage. Based on the results of these trials, conducted in an eight year period (2002-2010) using the sequenced slicing method for evaluating the efficacy of the aforementioned formulations against T. saginata cysticercus, it is possible to observe that, amongst the few molecules used in the chemotherapic treatment against T. saginata larvae, ALB-SO, administered in varied routes, dosages and treatment schemes, the studies conducted in 2008, 2009, and 2010, have a low therapeutic efficacy against C. bovis in Brazil, while ALBZ had insignificant efficacy values against T. saginata larvae parasitizing experimentally infected bovines. However, future studies using molecular biology will be necessary to assess whether the difference on the efficacy of the ALB-SO can be related to strain or another specific factor.

Seroprevalence of and risk factors for Toxoplasma gondii in sheep raised in the Jaboticabal microregion, São Paulo State, Brazil.

Seroprevalence of and risk factors for toxoplasmosis in sheep from different properties in the Jaboticabal microregion, São Paulo State, Brazil were determined. Antibodies to Toxoplasma gondii were found in sera of 52.0% of 488 sheep tested by indirect fluorescent antibody test (IFAT > or =64). T. gondii seropositivity in sheep was significantly associated with gender of the sheep, pasturing system, contact with cats, and the use of mineral supplements and the type of feed.