[Bovine leptospirosis in the South Bohemian Region].

In the years 1976 to 1979, 10 345 blood samples of clinically healthy cattle and aborting cows were examined; 11% of the samples contained positive antibody titers to L. grippotyphosa (7% in non-aborting cows, 3.2% in non-aborting heifers, 12% in aborting cows, 8% in aborting heifers). The samplings were repeated within the range of three weeks to three months: the antibody titer increased in 11.8% of samples, 10.9% of samples were unchanged and in 77.2% of samples the titers dropped. Out of 9918 blood samples taken after abortion, the titer 1 :800 for L. grippotyphosa occurred 269 times, titer 1 :1600 192 times, 1 :3200 61 times, 1 :6400 22 times, 1 :12800 10 times, 1 : 25 600 occurred twice. Most of the positive titers were recorded in March - 16%, in September, October and November it was about 14% and in the other months the value was still lower. In stables with a greater per cent of the positive titers of antibodies to L. grippotyphosa, mastitis of obscure etiology occurred, along with abortions at the end and beginning of gravidity. During incidental slaughters in slaughter-houses nephritis from parenchymatous to interstitial form was observed in seven cows with the titers higher than 1 :1600; the nephritis was accompanied by granular adipose dystrophies and numerous infarcts in kidneys, the bacteriological picture was negative.