Toxoplasma gondii in small ruminants in Northern Italy : prevalence and risk factors

Objective. The aim of the survey was to evaluate Toxoplasma gondii seroprevalence in small ruminants and possible risk factors associated with the infection. Materials and methods. Sera from 474 goats and 502 sheep reared on 42 farms in northern Italy were collected and tested for IgG antibodies to T. gondii by IFAT (indirect immunofluorescence antibody test). To identify risk factors, a binary logistic regression analysis of the variables was performed. An audit form about farm management was used. Results. Antibodies to T. gondii were found in 96.6% of goat farms and in 87.5% of sheep farms; 41.7% goats and 59.3% sheep resulted positive. Seroprevalence was significantly higher in sheep than in goats. Seroprevalence values were similar in goats from eastern and western areas, whereas goats from the southern area were at lower risk of infection. Saanen goats presented the lowest seroprevalence (30.7 %), whereas cross-breed exhibited the highest rate (48.7%). Goats from farms housing both sheep and goats had an infection risk 1.39 times higher than goats from farms that did not house sheep. Animals bred on intensive farms showed lower prevalence (22.1%) in comparison with those from extensive (45.6%) or semiintensive farms (60%). Sampling area was one of the strongest predictors of T. gondii infection in sheep flocks. Transhumant flocks showed a higher risk of infection by T. gondii compared with semi-intensive farms (66.8% vs. 38.4%). Conclusions. The highest T. gondii seroprevalence values were registered in transhumant flocks of sheep and in family businesses rearing goats. As these traditional activities represent an important resource for the conservation of the territory and its economy, management practices for a better control of the disease should be improved.