Causas de problemas reprodutivos em rebanhos caprinos e ovinos no Semiárido Nordestino, Brasil.

Abstract

Pathogens such as Leptospira sp. and Toxoplasma gondii were associated with reproductive failures in small ruminant herds causing serious economic losses. Thus, we sought to investigate the participation of Leptospira sp. and T. gondii in reproductive disorders in goats and sheep from properties located in the municipality of Salgueiro, Pernambuco, Northeastern Brazil. The dissertation was elaborated in two chapters. In Chapter I, the objective was to analyze the participation of Leptospira sp. in an abortion outbreak in small ruminants from eight farms located in the municipality of Salgueiro, Sertão Pernambuco, Brazil. The diagnosis of leptospirosis was performed based on serology (microscopic agglutination test - MAT), bacterial culture and polymerase chain reaction (PCR). From a total of 233 females in reproductive age, being 171 goats and 62 sheep, 12.3% (21/171) of the goats and 17.7% (11/62) of the sheep were positive in MAT. Antibody titers ranged from 50 to 200 and the most frequent serogroups were Castellonis (78.1%) and Grippotyphosa (15.6%). The DNA of Leptospira sp. was identified in 55.7% (44/79) of the vaginal secretion samples tested, 58.5% (38/65) of goats and 42.9% of sheep (6/14). Bacterial isolation was obtained in 37.9% of the 79 cultures of vaginal secretions, being 38.5% (25/65) from goats and 35.7% (5/14) from sheep. Of the 92 (39.5%) females related to abortions (76 goats and 16 sheep), 12 (13%) had anti- Leptospira sp. antibodies, 7 (9.2%) goats and 5 (31.3%) sheep. The serological, molecular, clinical and isolation findings suggest the possible association of abortions with the presence of the agent in the studied herds. In Chapter II, the participation of T. gondii in an abortion outbreak in goats and sheep from eight farms located in the municipality of Salgueiro - PE, in the Brazilian semiarid region, was studied. A total of 233 females of reproductive age, 171 goats and 62 sheep, were processed through indirect immunofluorescence reaction (IFAT), seeking the detection of IgG antibodies to T. gondii. 14% (24/171) of goats and 40.3% (25/62) of sheep were positive in the IFI. Antibody titers ranged from 64 to 8192. Of the 92 (39.5%) females related to abortions, 19 (20.7%) presented anti-T. gondii antibodies, being 12 (15.8%) goats and 7 (43.8%) sheep. The serology results with the clinical findings revealed the possible association of abortions with the presence of the agent in the studied herds. It is concluded that leptospirosis and toxoplasmosis can be the causes of reproductive disorders and abortions in goat and sheep herds in the semiarid region, requiring the adoption of prevention and control measures for these infections. It is recommended to implement improvements in sanitary and management practices, zootechnical control, and treatment in the case of leptospirosis as measures to control these diseases.