Bioverm® (Duddingtonia flagrans) is a fungal formulation indicated for controlling gastrointestinal nematodes in ruminants and horses, which has recently been authorized for commercialization in Brazil. The objective was to determine the efficiency of Bioverm® against larvae of gastrointestinal nematodes after passage through the gastrointestinal tract of cattle. Twelve animals were used, divided into two groups. In the treated group, a single dose of 1 g of Bioverm® per 10 kg of live weight (containing 105 chlamydospores of D. flagrans) was provided for each animal. Fecal samples were obtained from the animals in each group at 12, 24, 36, 48, 60 and 72 hours after administration. In assay A, 2 g of feces were added to Petri dishes containing 2% agar-water medium. In assay B, coprocultures were performed. In both assays, the peak of larval predation occurred within 48 hours after administration of Bioverm®. In assay A, a significant larval reduction (P < 0.05) was seen at 48 h (88.2%). In assay B, significant reductions (P < 0.05) were seen at 36 h (43.7%) and 48 h (82.3%). Bioverm® showed high predatory capacity after passage through the gastrointestinal tract of cattle and was effective for controlling gastrointestinal nematodes.
1 January 2021 in Revista Brasileira de Parasitologia Veterinária
Aimed with this study to evaluate vertical transmission of Neospora caninum in naturally infected sheep and to monitor the kinetics of antibodies against this protozoon in their lambs. Therefore, 48 pregnant ewes, from five herds, were divided into two groups: G1 - positive for anti-N. caninum antibodies, with 19 animals; and G2 - seronegative, with 29 animals. Blood samples were taken from the ewes and their lambs, immediately after birth, before ingesting colostrum, and 2, 7, 14, 21, 28, 35, 42, 49 and 56 days after birth. Analysis on serum antibodies was performed using the indirect immunofluorescent antibody test. Among the 19 seropositive mothers, six (31.6%) gave birth to lambs seropositive before ingesting colostrum and it was found that these lambs remained positive until the end of the study (56 days). Only one of the lambs, from a ewe that presented an antibody titer of 200, seroconverted after ingestion of colostrum. All the lambs that had been born from negative mothers remained negative throughout the experimental period. It was concluded that transplacental transmission was an important form of diffusion of N. caninum in the herds studied and that seropositive lambs maintained circulating antibodies during the period analyzed.
Toxoplasmosis, caused by Toxoplasma gondii, poses a significant threat to sheep flocks, affecting reproductive performance and meat quality, and leading to economic losses. This study aimed to evaluate the correlation between anti-T. gondii IgG antibodies in the serum and colostrum of naturally infected ewes and to assess passive immunity in newborn lambs. Blood and colostrum samples were collected from 162 ewes and 182 lambs across 20 sheep farms in Paraíba, Brazil. Samples were tested for anti-T. gondii and anti-Neospora caninum IgG using indirect fluorescence antibody tests (IFATs), with titers ≥ 1:64 considered positive. Among the ewes, 45.1% tested positive for anti-T. gondii IgG in serum, with titers ranging from 1:64 to 1:16,384. The colostrum from 94.6% of the ewes also tested positive, although 74% had higher titers in their serum than in their colostrum. Concordance between serum and colostrum was high, with a kappa coefficient of 0.950. Lamb serum showed a perfect agreement with maternal colostrum (kappa = 0.962), demonstrating effective passive transfer of antibodies. This study confirms that colostrum is a reliable matrix for detecting anti-T. gondii antibodies and assessing passive immunity in lambs. The high concordance between serum, colostrum, and lamb titers suggests that IFATs on colostrum can be a practical tool for monitoring maternal antibody transfer, contributing to the better management of T. gondii infections in sheep flocks.
1 January 2021 in Revista Brasileira de Parasitologia Veterinária
The effectiveness of four anthelmintic classes on cattle gastrointestinal nematodes in the semi-arid region of Paraiba State, Brazil, was evaluated. Twenty farms were used, testing 40 animals in each one, totaling 800 animals. Cattle were divided into four groups composed with ten animals: I, treated with albendazole sulfoxide 15%; II, treated with ivermectin 1%; III, treated with closantel 25%; IV, treated with levamisole hydrochloride 7.5%. All treatments were administered subcutaneously. For the Fecal Egg Count Reduction Test (FECRT), individual fecal samples were collected on days 0 and 14, and sent for analysis of egg count per gram of feces (EPG) and larval cultures. It was observed that multiresistance was present in 95% (19/20) of the farms. Resistance to ivermectin and albendazole was observed in 95% (19/20), to closantel in 75% (15/20) and to levamisole in 20% (4/20). The most used management system was semi-intensive (75%; 15/20) and the ivermectin was the most reported drug for controlling helminths (65%; 13/20). Haemonchus spp. was the most prevalent helminth genus. It was concluded that the anthelmintic resistance of bovine gastrointestinal nematodes is high in the semi-arid of Paraíba State, Brazil, with multiresistance observed mainly to ivermectin, albendazole and closantel.
Hepatozoonosis is caused by protozoa of the genus Hepatozoon. In dogs, the infection is caused mainly by Hepatozoon canis, and there are a few descriptions of the prevalence of this infection in the Northeast region of Brazil, especially in the semi-arid region. Therefore, we aimed to determine the prevalence of Hepatozoon canis infection in dogs in the rural area of Sousa, Paraíba, Brazil, as well as to determine the possible clinical and epidemiological aspects of this infection. Ninety-eight dogs in the rural zone of the municipality of Sousa that were at least 4 months old were evaluated, regardless of their breed or gender. Clinical examinations were carried out, and samples of systemic and peripheral blood were collected to determine the presence of the parasite in blood smears and carry out hemograms. In addition, epidemiological questionnaires about animal health and food management were completed. The prevalence of H. canis infections in dogs was 8.1% (8/98). There were three main changes in the hematological status: thrombocytopenia, anemia and hyperproteinemia, mainly related to percentage of leukocyte infection ≥5%, and also to the presence of clinical signs such as mucopurulent secretion, lymphadenomegaly, dry skin, pale mucous membranes, and lean or cachectic body score.