Seroprevalence of Toxoplasma gondii and Neospora caninum in wild and domestic ruminants sharing pastures in Galicia (Northwest Spain).

The prevalence of antibodies to the protozoan parasites Toxoplasma gondii and Neospora caninum were investigated by the direct agglutination test (DAT) and cELISA, respectively, in 160 roe deer (Capreolus capreolus), 177 sheep and 178 cattle sharing pastures in Galicia (Northwest Spain). The seroprevalence for T. gondii was 13.7% in roe deer, 57% in sheep and 7.3% in cattle. The seroprevalence for N. canimum was 6.8%, 10.1% and 24.1% in roe deer, sheep and cattle, respectively. Statistically significant differences were observed between sheep and the other species for T. gondii and between cattle and the other ruminants for N. caninum. Only 19/515 animals were positive for both, T. gondii and N. caninum. Statistically significant differences were observed among different geographical areas for T. gondii but not for Neospora, seroprevalence being higher in the coastal area lower than in other areas. This study reveals a widespread exposure to T. gondii in Galician ruminants, and therefore, those species, particularly sheep, should be regarded as a potential source of infection for humans.

Field evaluation for anthelmintic-resistant ovine gastrointestinal nematodes by in vitro and in vivo assays.

A coprological survey to analyze the presence of flock resistance to benzimidazoles (BZ) and macrocyclic lactones (ML) was performed in sheep under field conditions. Fecal samples were collected from 2,625 sheep in 72 commercial farms from Galicia (NW Spain). The in vitro (FECRT, fecal egg count reduction test) and in vivo (EHA, egg hatch assay, and LFIA, larval feeding inhibition assay) tests were used to assess the efficacy of these anthelmintics. Coprocultures were also developed to obtain knowledge on the main genera of trichostrongylid nematoda prior to, and after, the administration of the anthelmintics. By using the FECRT, BZ resistance was observed in 13 (18%) flocks, whereas ML resistance was only detected in 2 (3%) farms. The number of resistant flocks to BZ was 21 (29%) by using the EHA and 7 (10%) by means of the LFIA. None of the flocks used in this study showed simultaneous resistance to both employed anthelmintics. The results from the in vitro and in vivo tests revealed that 92% of the flocks FECRT resistant to BZ were also resistant with the EHA. The LFIA confirmed all the farms resistant to ML by using the in vivo test. After the administration of BZ, nematode larvae belonging to Teladorsagia circumcincta (32.2%), Trichostrongylus spp. (29%), Nematodirus spp. (6.5%), and Chabertia ovis (3.2%) were identified. In the flocks receiving ML, only T. circumcincta was identified (57%). We recommend the use of in vitro tests because they are more efficient. As the use of macrocyclic lactones is increasing in this region, further investigation is needed for detecting resistance to the anthelmintic family compounds by the LFIA.