Occurrence of antibodies to Toxoplasma gondii in water buffaloes and meat cattle in Rio Grande do Sul State, southern Brazil.

Serum samples from 169 water buffaloes and 121 beef cattle were analyzed for antibodies to T. gondii by an indirect fluorescent antibody test (IFAT). Positive results were obtained in 27.2% of water buffaloes and 17.4% of cattle. Statistical analysis indicated significant differences between the prevalence in cattle and buffalo (p ≤ 0.05). The highest titres found in positive animals were 1:256 (buffaloes) and 1:64 (cattle). In both bovine species, toxoplasmosis frequency in young animals (less than 2 years old) was lower compared to older individuals, although the differences seen in cattle were not statistically significant.

Análise in vitro da eficácia do amitraz sobre populações de Rhipicephalus (Boophilus) microplus (Canestrini, 1887) da região sul do Rio Grande do Sul / In vitro analysis of amitraz efficacy against Rhipicephalus (Boophilus) microplus (Canestrini, 1887) populations of southern region of Rio Grande do Sul state

Formulações comerciais à base de amitraz são muito utilizadas como acaricidas na Região Sul do Rio Grande do Sul, contudo sem maiores estudos da sua eficácia nessa região. O presente estudo objetivou estimar a frequência de populações de R. (B.) microplus resistente ao amitraz na Região Sul do Rio Grande do Sul, e comparar a eficácia de cinco produtos comerciais à base desse princípio ativo. Os resultados demonstraram que, em 23% das populações estudadas, o amitraz teve uma eficácia inferior a 69%. Em 29% dessas amostras de carrapatos, o grau de eficácia foi igual a zero, sugerindo a presença de altos níveis de resistência ao amitraz. Além disso, o produto comercial mais utilizado na região demonstra o menor índice de eficácia. Esses resultados alertam sobre a possibilidade da dispersão de populações de carrapatos resistentes, o que justifica a necessidade de direcionar pesquisas visando a novas alternativas e produtos para o controle desse parasito.(AU)

Commercial formulation of the amitraz is the most used acaricide in the southern region of Rio Grande do Sul State, however scientiic data about the efficacy of these products in this region are sparse. he aim of the present study was to evaluate the frequency of R. (B.) microplus populations resistant to amitraz acaricides in the Southern region of Rio Grande do Sul State. So, the efficacies of five commercial products containing amitraz were compared. Results showed that the efficacy of amitraz acaricides was lower than 69% in 23% of studied populations. Nearly 29% of the tick samples showed an acaricide efficacy equal to zero, suggesting the presence of a high level of resistance to amitraz. Moreover, the most used commercial product in the region showed the lowest efficacy index. hese results alert about the possible spreading of resistant on tick populations and justify research directed toward the search for alternative products to control this parasite.(AU)

[Risk factors and prevalence of antibodies anti-Neospora caninum in urban and rural dogs from Rio Grande do Sul, Brazil]. / Fatores de risco e prevalência de anticorpos anti-Neospora caninum em cães urbanos e rurais do Rio Grande do Sul, Brasil.

Serum samples from 339 dogs from rural (beef and dairy farms) and urban areas of Municipality of Pelotas, RS, were tested by indirect fluorescent antibody test to verify the presence of antibodies anti-Neospora caninum. Data from dogs took part of an epidemiologic questionnaire to identify possible risk factors associated with the seropositivity. Antibodies anti-N. caninum were found 15.6% (53/339) of serum samples, with 5.5% (6/109) of positive dogs from urban area and 20.4% (47/230) from rural area. The analysis multivariate of the risk factors in showed that rural dogs have 3.5 times more chance of contact with the parasite than urban dogs. Dogs with more than 3-years old have a greater risk (OD = 4.1) to be positive for N. caninum than dogs with less than 3-years. Rural dogs from beef farms presented greater risk (OD = 2.8) to be positive when compared with dogs from dairy farms. Seropositivity rate increased 2.2 times in farms which the carcasses of dead animals and aborted fetus were not appropriately removed. N. caninum is present in the southern region of the Rio Grande do Sul, infecting urban and rural dogs.