Toxoplasma gondii is an infective parasite that causes reproductive disorders such as abortion, fetal mummification, birth of weak offspring, and stillbirth, thereby causing economic losses to sheep production. The northeastern region of Brazil has approximately 171 million small ruminants, of which 5.4% are sheep. The present study aimed at determining the rate of occurrence of T. gondii in sheep flocks on 60 farms in 19 municipalities in the three mesoregions (eastern, semi-arid, and sertão or backlands) of the state of Sergipe, Brazil, and the risk factors associated with this infection. Serum samples were collected between 2011 and 2012, from 60 farms located in 19 municipalities in the three mesoregions: 680 in the eastern region, 280 in the semi-arid region, and 240 in the backlands, totaling 1,200 samples (990 females and 210 males). Anti-T. gondii antibodies were detected by means of the indirect fluorescence antibody test (IFAT ≥ 64). The highest occurrence was detected in the eastern region (45.3%, p = 0.001). On farms with subsistence production, the risk of having animals infected by T. gondii was approximately twice as high as on breeding/rebreeding/fattening farms (OR: 3.03; CI: 1.97-4.68). There was a significant lack of sanitary care, such as absence of a dunghill (p = 0.000; OR: 1.60; CI: 1.26-2.03), quarantine (p = 0.000; OR: 1.87; CI: 1.45-2.41) and disinfection (p = 0.003; OR: 1.46; CI: 1.13-1.88). Regarding feeding, the risk of infection was 1.74 and 1.37 times higher in places that used a trough and/or that cats could access, respectively. The presente study allows the conclusions that T. gondii is found on farms in the three mesoregions of the state of Sergipe and that environmental and management factors have an influence on sheep infection.

Triclabendazole is the drug of choice against Fasciola spp. infections in humans and animals. However, parasitic resistance against triclabendazole is spreading in the veterinary field. The objective of this study was to assess of flukicide efficacy of triclabendazole through evaluation of the histopathology of Fasciola hepatica adult fluke’s specimens. For this, the efficacy test was performed on naturally infected sheep treated with triclabendazole (Fazinex®) at the dose recommended for F. hepatica, in which the flukes recovered at necropsy on the 7th day post-treatment and separated for histological examination. The teguments and intestines from F. hepatica recovered from treated and control sheep were examined by microscopy. In the outer and inner parts of the tegument, edema and swelling of its structural components are noted. The spines in the tegument were enlarged, swollen, take on a more rounded shape and have changes in color, perceiving the eosinophilic dye in greater concentration. There was a detachment of the brush border of the intestinal epithelium and the accumulation of microvilli of the apical part of the epithelium in the intestinal lumen. The cellular structures of the intestinal epithelium were melted. The results indicated that the teguments and intestines of F. hepatica were severely affected by triclabendazole and demonstrated the importance of the use of histopathology for the diagnosis of therapeutic efficacy in field strains.