[Findings in an outbreak of salmonellosis due to S. dublin in veal calves in the province of Gelderland (author's transl)].

An outbreak of salmonellosis caused by S. dublin has been prevalent in the Province of Gelderland ever since the end of 1975. The clinical picture is marked by general disease and respiratory symptoms, variations in temperature and diarrhoea which was present in not more than approximately 20 per cent of the cases. The most satisfactory results of treatment were obtained on administration of a sulphamethoxazole trimethoprim compound and colistin. Mortality averaged 16 per cent, the flock continuing to be affected with the disease for six weeks. In addition to enteritis, septicaemia and pneumonia were outstanding features in post-mortem studies. S. dublin was detected particularly in the liver, spleen and kidney. The sensitivity pattern showed a marked decrease during the past six to seven years, particularly sensitivity to chloramphenicol, tetracycline and ampicillin. The greater part of the strains were only sensitive to colistin, furazolidone and a sulphamethoxazole trimethoprim compound. This increase in resistance is discussed, and it is attributed to mass administration of antibodies rather than to transfer of resistance due to R-factors.