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.

The objective was to describe the seroprevalence of anti-Neospora caninum antibodies in goats and sheep slaughtered in the state of Paraíba and to identify possible associated factors with the infections. Two hundred twenty-nine samples from goats and two hundred five from sheep were analyzed by Indirect Immunofluorescence Reaction (IFAT) using a cutoff point of 1:50. The presence of anti-N. caninum antibodies was identified in 28.4% (65/ 229; 95% Confidence Interval: 22.6-34.2) of the goat samples and in 12.7% (26/ 205; 95% CI: 8.2 – 17.2) of the sheep samples. Contact between goats and dogs (Odds ratio 4.81; CI 1.13 – 2.67; p = 0.041) and cattle (OR. 1.87; CI 1.13 – 2.67; p = 0.002) was identified as a risk factor for goats and contact between sheep and dogs (OR 2.32; CI 1.58 – 3.14; p = 0.026) and history of abortion (OR 1.94; CI 1.28 – 2.90; p = 0.001) was considered a risk factor for sheep. The study revealed a high seroprevalence of anti-N. caninum antibodies in slaughtered goats and sheep in Paraíba. Risk factors such as contact with dogs/cattle and abortion history underscore the need for preventive measures to control infection and enhance animal health management.

Cattle tick fever (CTF), caused by Anaplasma marginale, Babesia bovis and Babesia bigemina, remains a sanitary and economic challenge for cattle farming in Brazil. Thus, this study evaluated the prevalence, regional distribution, co-infection patterns, and risk factors associated with CTF causative agents in cattle the semi-arid region of Paraíba, the semi-arid region of Ceará, and the Tropical Humid region of Paraíba, Northeast Brazil. Blood samples were collected from 336 cattle, from 60 farms, and analyzed by means of conventional PCR and nested-PCR, while epidemiological data were obtained through questionnaires applied to producers. The overall infection prevalence by at least one pathogen was 82.7% (278/336), with higher rates in the tropical humid region of Paraíba at 94.8% (109/115), followed by the semi-arid region of Ceará, with 88.1% (89/101) and the semi-arid region of Paraíba with 66.6% (80/120). Co-infections were frequent, especially the association between A. marginale and B. bigemina, detected in 23.2% (78/336) of the animals, while triple infections occurred in 15.8% (53/336) and were most frequent in the semi-arid region of Ceará at 21.8% (22/101). The semi-arid region of Paraíba had the fewest entirely positive properties (7/20) and the highest number of entirely negative properties (2/20). The tropical humid region of Paraíba had the highest number of entirely positive properties (17/21), with no properties entirely free of CTF agents. Multivariate analysis identified the presence of horn fly (OR = 7.23; CI 3.05–18.86; 95% CI), needle reuse (OR = 5.8; CI: 2.62–13.90; 95% CI), animal purchase and introduction without quarantine (OR = 5.4; CI: 2.17–14.93; 95% CI), and pasture sharing (OR = 3.21; CI: 1.08–11.25; 95% CI) as risk factors, while beef herds showed lower susceptibility (OR = 0.28; CI: 0.15–0.52; 95% CI). These findings demonstrate that infections by CTF causative agents are endemic but exhibit region-specific epidemiological patterns, reflecting the combined effects of climate and management practices, and localized transmission foci that may be intensified by commercial cattle movement.

Background: Neospora caninum and Toxoplasma gondii are globally distributed intracellular protozoa of veterinary and public health importance. Dogs are the definitive hosts of N. caninum and act as epidemiological sentinels of environmental contamination by T. gondii. However, information regarding canine exposure to these protozoa in Espírito Santo State, Brazil, remains limited. Therefore, this study investigated the seroprevalence of anti-N. caninum and anti-T. gondii antibodies in dogs from an urban area of Espírito Santo State and evaluated factors associated with infection. Materials, Method & Results: A total of 103 canine serum samples were analyzed by the Indirect Fluorescent Antibody Test (IFAT). Epidemiological information regarding sanitary management, feeding practices, housing conditions, and contact with other animal species was obtained through questionnaires applied to dog owners. Descriptive statistical analysis was performed to determine seroprevalence, followed by univariate and multivariate analyses to identify factors associated with seropositivity. Anti-Neospora caninum antibodies were detected in 24 (23.3%) dogs, whereas 33 (32.0%) were seropositive for Toxoplasma gondii. Coinfection was identified in 9 (8.7%) animals. For N. caninum, antibody titers ranged from 1:50 to 1:3200, with predominance of the 1:50 titer. For T. gondii, titers ranged from 1:16 to 1:2048, with the highest frequencies at 1:16 and 1:128. None of the evaluated variables was associated with N. caninum seropositivity (P > 0.05). For T. gondii, dogs living in houses showed a significantly higher seroprevalence than those living in apartments in the univariate analysis (P ≤ 0.05); however, no significant association remained after multivariate logistic regression. Discussion: The seroprevalence observed in this study is consistent with previous reports demonstrating the circulation of Neospora caninum and Toxoplasma gondii in canine populations from different regions of Brazil. The wide variation reported among studies probably reflects differences in environmental conditions, management practices, diagnostic cut-off values, and characteristics of the evaluated canine populations. Previous studies conducted in Espírito Santo have also demonstrated exposure of dogs to both protozoa, confirming their circulation in different canine populations throughout the state. Dogs play an important epidemiological role because they are the definitive hosts of N. caninum and serve as sentinels of environmental contamination by T. gondii. The predominance of low anti-N. caninum antibody titers suggests previous exposure in most seropositive animals, whereas the heterogeneous distribution of anti-T. gondii titers may indicate differences in antigenic stimulation or host immune response. The occurrence of coinfection supports the simultaneous circulation of both protozoa in the same urban environment. Although household type was associated with T. gondii seropositivity in the univariate analysis, this association was not maintained in the multivariate model, suggesting that exposure is influenced by multiple environmental or behavioral factors. Overall, the high seroprevalence of anti-T. gondii and anti-N. caninum antibodies, together with the detection of coinfection, demonstrates the circulation of both protozoa in the studied urban environment. These findings reinforce the role of dogs as epidemiological sentinels and highlight the importance of continued surveillance and preventive measures within a One Health perspective. Keywords: neosporosis, toxoplasmosis, sentinel animals, urban environment, One Health.

O presente estudo objetivou determinar a frequência de hemoparasitos em pequenos animais de três cidades da região do Cariri Cearense, assim como os achados epidemiológicos e hematológicos associados às infecções. Foram analisados 607 laudos hematológicos provenientes de amostras enviadas ao Laboratório Veterinário Lab Vet, localizado em Juazeiro do Norte-CE. As amostras foram analisadas utilizando-se o analisador hematológico BC 2800 Mindray, com pesquisa de hemoparasitos em esfregaços sanguíneos. Foram coletados dados relativos aos animais, como sexo, idade, raça e cidade de origem. A frequência de hemoparasitos foi de 7,41% (45/607), sendo Anaplasma spp. o gênero mais frequente. Em cães, a frequência de animais positivos foi de 6,58% (32/488), sendo Ehrlichia spp. (34,4% – 11/32), Anaplasma spp. (28,1% – 9/32) e Hepatozoon spp. (25% – 8/32) os mais frequentes. Em gatos, a frequência de hemoparasitos foi de 10,74% (13/119), com Anaplasma spp. (84,6% – 11/13) e Mycoplasma spp. (15,3% – 2/13) sendo os mais frequentes. As principais alterações hematológicas foram anemia e trombocitopenia, e animais com até 12 meses de idade apresentaram maior probabilidade de infecção. Concluiu-se que são expressivas as infecções pelos gêneros de hemoparasitos Ehrlichia, Anaplasma, Hepatozoon e Mycoplasma em pequenos animais no Cariri do Ceará, sendo necessário incluir essas infecções na lista de diagnósticos diferenciais da região bem como alertar os tutores sobre a importância do controle dos parasitos vetores desses hemoparasitos, forma mais eficaz de prevenir essas infecções.

This study described and characterized clinical cases and outbreaks of neosporosis in cattle, sheep, and goats, considering the geographical distribution, clinical manifestations, lesions, and diagnostic methods reported in different regions of the world. An independent systematic review was conducted following the standard guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Fifteen studies met the inclusion criteria: case reports and short communications published until December 2024, indicating the origin of the sampled animals; written in English, Portuguese, or Spanish; and published in indexed peer-reviewed journals. Case reports originated from four continents: America (North, Central and South), Europe, Asia, and Oceania. America (North, Central and South) had the highest number of case reports (60%; 9/15). Cattle were the most frequently reported species with neosporosis cases (46.7%; 7/15), while small ruminants accounted for eight cases (53.3%; 8/15). The most common clinical sign was abortion (86.6%; 13/15), and the most affected organs were the brain (93.3%; 14/15), heart (66.6%; 10/15), liver (40%; 6/15), and lungs (33.3%; 5/15). The most used diagnostic methods were histopathology (100%; 15/15) and immunohistochemistry (80%; 12/15). The most frequent microscopic findings included mononuclear cell infiltrates in the nervous tissues (66.6%; 10/15) and gliosis (44.6%; 7/15). Neosporosis showed wide geographical distribution, mainly affecting cattle in the Americas, with abortion as the main clinical sign and the brain as the most affected organ; diagnosis based on histopathology and immunohistochemistry, highlighting the importance of this disease in livestock production.