Outbreak of Salmonella Pullorum on a laying poultry farm in the Netherlands

Pathological examination showed abnormal organs, such as an enlarged liver and stalked egg follicles. Large quantities of the bacterium Salmonella Pullorum were cultured from various organs. In addition, GD carried out blood tests with a serological test that is used in monitoring. At 70 weeks of age, 61% of the blood samples were positive for antibodies and at 84 weeks, 100% of the flock were positive. The couple had been vaccinated three times during the rearing period with a live vaccine against Salmonella Enteritidis and Salmonella Typhimurium. Histological examination of organ tissue from hens with nervous symptoms revealed foci of inflammation in their brains in which salmonella bacteria were detected. The bacteria found showed resistance to several types of antibiotics in the antibiotic sensitivity test. That is why the focus was first on combating blood mites and selecting out sick animals. When this had insufficient effect, a live salmonella vaccine, directed against ...