Prevalence of antibodies to toxoplasma in farm animals in the Netherlands and its implication for meat inspection.

A serological survey on toxoplasmosis was carried out amongst horses, sheep, cattle, pigs and poultry in the Netherlands. Sera were obtained from slaughter animals and the results were compared with those of previous studies of this kind in the Netherlands. In horses and cattle the percentage of seropositive animals remained the same in the past 20 years. In sheep and particularly in pigs, however, a remarkable decline of seropositive animals was found. This is probably due to the age of the animals examined and a change in present day methods of farming. In poultry it was shown that only free scratching hens were seropositive in up to 30 per cent of the animals tested, whereas broilers and battery animals were seronegative. Since as yet no individual control measures in the slaughterhouse exist with regard to toxoplasmosis it is recommended to carry out periodic epizootiological surveys amongst farm animals to be able to follow trends of the infection.