The aim of the present study was to find out the diversity of Eimeria species in cattle herds in the semiarid region of Brazil. Forty cattle fecal samples were collected from 20 farms in the Paraíba State, Northeast Brazil, and examined by centrifugation-floatation technique in sucrose solution. From each positive animal, 20 oocysts were photographed and measured. Infection by Eimeria spp. was detected in 17.12% (137/800) of the samples analyzed. All the farms had at least one animal that was positive for Eimeria spp. (100%; 20/20). In total, 2740 coccidia were photographed and measured. The species detected were: Eimeria bovis (35.1%); Eimeria canadensis (17.48%); Eimeria auburnensis (14.7%); Eimeria ellipsoidalis (9.7%); Eimeria zuernii (7.22%); Eimeria brasiliensis (4.56%); Eimeria bukidnonensis (3.97%); Eimeria illinoisensis (2.91%); Eimeria wyomingensis (1.42%); Eimeria alabamensis (1.27%); Eimeria cylindrica (0.76%); Eimeria pellita (0.54%); Eimeria ildefonsoi (0.21%); and Eimeria subspherica (0.07%). It was concluded that cattle in the semiarid region of Brazil were parasitized by 14 species of Eimeria. It is thinked that the sanitary management employed, as well as the system used for raising these animals, is the crucial point that leads to high rates of infection in this region.

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.

We aimed to evaluate a Brazilian commercial formulation of the fungus Duddingtonia agrans (Bioverm®) for controlling gastrointestinal nematodes in sheep kept on native pasture in the Caatinga biome, in the semiarid region of Brazil. Twenty ewes, aged between 12 and 18 months, were divided into two groups. In the treated group, each animal received 1 g of the Bioverm® product for each 10 kg of live weight, daily, together with commercial feed, for six months. In the control group, the animals received feed without Bioverm®. Each group remained throughout the experiment in a 1.2 ha paddock. Monthly counts of eggs per gram of feces (EPG), fecal cultures, packed cell volume (PCV), weight measurements and collection of leaf mass from the pasture were performed. There was greater reduction in EPG, greater weight gain and less infestation by infective larvae in the paddock of the Bioverm® group, compared with the control group (p < 0.05). There was no signi cant difference (p ≥ 0.05) in the mean PCV percentage between the Bioverm® and control groups. In coprocultures, Haemonchus sp. was the most prevalent helminth. Bioverm® (D. agrans) was e cient for biological control of sheep gastrointestinal nematodes in the semiarid region of Brazil.

We aimed to evaluate a Brazilian commercial formulation of the fungus Duddingtonia flagrans (Bioverm®) for controlling gastrointestinal nematodes in sheep kept on native pasture in the Caatinga biome, in the semiarid region of Brazil. Twenty ewes, aged between 12 and 18 months, were divided into two groups. In the treated group, each animal received 1 g of the Bioverm® product for each 10 kg of live weight, daily, together with commercial feed, for six months. In the control group, the animals received feed without Bioverm®. Each group remained throughout the experiment in a 1.2 ha paddock. Monthly counts of eggs per gram of feces (EPG), fecal cultures, packed cell volume (PCV), weight measurements and collection of leaf mass from the pasture were performed. There was greater reduction in EPG, greater weight gain and less infestation by infective larvae in the paddock of the Bioverm® group, compared with the control group (p < 0.05). There was no significant difference (p ≥ 0.05) in the mean PCV percentage between the Bioverm® and control groups. In coprocultures, Haemonchus sp. was the most prevalent helminth. Bioverm® (D. flagrans) was efficient for biological control of sheep gastrointestinal nematodes in the semiarid region of Brazil.

<p><strong>INTRODUÇÃO: </strong>A bovinocultura ocupa lugar de destaque no cenário mundial, sendo o Brasil um dos maiores produtores de leite e exportadores de carne bovina. Na Paraíba, a produção de ruminantes é uma atividade viável, fornecendo uma das principais fontes de proteína animal para a alimentação humana, entretanto, existem alguns limitantes na produtividade dos rebanhos, dentre eles, as endoparasitoses gastrintestinais. Essas enfermidades são responsáveis pela diminuição no consumo de alimentos e absorção de nutrientes, crescimento retardado e consequentemente queda na produção de carne e leite, além de mortalidade dos animais. A principal forma de controle parasitário é feita pelo uso de compostos químicos de amplo espectro de atuação, no entanto, a utilização irracional de anti-helmínticos vem contribuindo para a resistência dos parasitos gastrintestinais. <strong>OBJETIVOS: </strong>Avaliar a eficácia de anti-helmínticos sobre nematódeos gastrintestinais de bovinos no estado da Paraíba e determinar a incidência dos gêneros de helmintos gastrintestinais nos rebanhos bovinos estudados. <strong>METODOLOGIA: </strong>Foram realizadas coletas em dez propriedades, de cada propriedade, foram coletadas fezes de 40 animais, de ambos os sexos, sem tratamento anti-helmíntico por pelo menos três meses. Estes, foram divididos em quatro grupos, tratados com quatro fármacos anti-helmínticos diferentes, sendo o grupo I tratado com cloridrato de levamisol a 7,5% (1 mL/20 kg), o grupo II, com ivermectina a 1% (1 mL/50 kg), o grupo III, com albendazol a 10% (1 mL/ 40 kg) e o grupo IV, com closantel a 25% (1 mL/50 kg), todos pela via intramuscular. As amostras fecais foram coletadas diretamente da ampola retal, armazenadas e identificadas em sacos plásticos e enviadas para o Laboratório de Parasitologia Veterinária do Instituto Federal da Paraíba para a realização das análises. Foram realizadas a contagem de ovos por grama de fezes (OPG) do dia 0 e dia 10 e a obtenção de larvas infectantes por meio de coproculturas. Para a determinação da eficiência dos tratamentos, utilizou-se o teste de Redução da Contagem de Ovos Fecais (RCOF) pela seguinte fórmula: RCOF=[1-(OPGf /OPGi )]x100. Onde: OPGf = média do OPG final; OPGi = média do OPG inicial. <strong>RESULTADOS E DISCUSSÃO: </strong>Multirresistência foi observada em todas as propriedades avaliadas, com 40% (4/10) apresentando resistência a duas drogas, 50% (5/10) apresentando resistência a três drogas e 10%  (1/10) apresentando resistência à todos os medicamentos avaliados. Observou-se que o levamisol foi altamente eficaz em 30% (3/10) das propriedades, enquanto a ivermectina e o albendazol apresentaram a menor eficácia, sendo considerados insuficientemente ativos em 90% (9/10) das propriedades. O closantel foi eficaz em apenas 30% (3/10) das propriedades. Foi observada a presença de quatro gêneros de helmintos, sendo <em>Haemonchus </em>spp. o mais prevalente, seguido por <em>Trichostrongylus</em> spp., <em>Oesophagostomum </em>sp. e <em>Strongyloides </em>spp. <strong>CONCLUSÃO: </strong>Os nematódeos gastrintestinais de bovinos na Paraíba estão altamente resistentes a ivermectina, albendazol e closantel. Apesar do levamisol apresentar-se como o fármaco que reduziu o maior número de ovos, traços de resistências a este já são evidenciados. <strong>Palavras-chave: </strong>Anti-helmíntico.<strong> </strong>Resistência. Ruminantes.</p>

The aim of the present study was to carry out an epidemiological survey on gastrointestinal infections by nematodes and coccidia in cattle herds in the semiarid region of Paraíba, northeastern Brazil. A total of 832 cattle were sampled, of both sexes and different ages, on 21 farms in 21 municipalities in the state of Paraíba, Brazil. Fecal samples were collected individually to perform eggs per gram (EPG) and oocysts per gram (OoPG) counts in feces, and to perform fecal cultures. To assess factors associated with nematode and coccidia infections, epidemiological survey forms were applied to the farmers. The total frequency of infections by nematodes was 59.6% (496/832) and it was 36.9% (307/832) for coccidia. The levels of infection by nematodes and coccidia were most frequently low (EPG < 300; OoPG < 1,000), in 72.4% (359/496) and 75.2% (231/307), respectively. The most frequent nematode genera was Haemonchus spp. (78.8%). The risk factors for nematode infections in cattle were beef production trait (odds ratio = 2.99) and extensive rearing system (odds ratio = 3.8); the factors for coccidia were age ≤ 12 months (odds ratio = 2.9) and body score between 1 and 2 (odds ratio = 5.2). These results prove that there are high frequencies of gastrointestinal infections by nematodes and coccidia in cattle herds in the semiarid region of Paraíba, with predominantly low levels of infection. However, given the importance of subclinical infections, adjustments to sanitary management measures can contribute to reduction of parasite indices and better performance among the animals, thus generating greater profitability for farmers.

Rhipicephalus microplus, also known as the cattle tick, is the parasite with the greatest impact on cattle in Brazil. The most common method for controlling this tick is the application of synthetic chemical acaricides, especially ivermectin, which belongs to the group of macrocyclic lactones (MLs). However, because ivermectin is widely used, there is concern about the development of cross-resistance within this chemical class. Thus, engorged females were collected from farms with a history of resistance to ivermectin, which was the only one among the MLs that was used as an anthelmintic drug. Using the larval immersion test (LIT) technique, bioassays were performed with ivermectin, moxidectin and eprinomectin on populations of R. microplus from the semiarid region of the states of Paraíba and Ceará. Epidemiological questionnaires were applied to collect information about tick control management. All the evaluated populations showed cross-resistance between ivermectin and moxidectin, but only one population showed cross-resistance between ivermectin and eprinomectin. Weekly or monthly administration of injectable 1% ivermectin on farms was reported. It was concluded that the frequent use of ivermectin may lead to the development of cross-resistance to moxidectin. For eprinomectin, despite the structural similarity, cross-resistance was not observed in three tick populations.

Rhipicephalus microplus, also known as the cattle tick, is the parasite with the greatest impact on cattle in Brazil. The most common method for controlling this tick is the application of synthetic chemical acaricides, especially ivermectin, which belongs to the group of macrocyclic lactones (MLs). However, because ivermectin is widely used, there is concern about the development of cross-resistance within this chemical class. Thus, engorged females were collected from farms with a history of resistance to ivermectin, which was the only one among the MLs that was used as an anthelmintic drug. Using the larval immersion test (LIT) technique, bioassays were performed with ivermectin, moxidectin and eprinomectin on populations of R. microplus from the semiarid region of the states of Paraíba and Ceará. Epidemiological questionnaires were applied to collect information about tick control management. All the evaluated populations showed cross-resistance between ivermectin and moxidectin, but only one population showed cross-resistance between ivermectin and eprinomectin. Weekly or monthly administration of injectable 1% ivermectin on farms was reported. It was concluded that the frequent use of ivermectin may lead to the development of cross-resistance to moxidectin. For eprinomectin, despite the structural similarity, cross-resistance was not observed in three tick populations.