Susceptibility to secondary bacterial infections in growing pigs as an early response in ochratoxicosis

Mycotoxic nephropathy was induced in twelve 14 kg pigs fed a dietary compon ent, moulded by Aspergillus ochraceus and contributing ochratoxin A at 1 or 3 ppm for up to 3 weeks. Concurrently, salmonellosis arose spontaneously i n all six animals treated at 3 ppm and all died between days 15 and 17. Two of the six pigs in the 1 ppm group died similarly but the rest, and all of six control animals, were unaffected Clinical biochemistry and histology r evealed changes typical of renal ochratoxicosis in all ochratoxin-treated p igs. Clinical and pathomorphological changes typical of salmonellosis were evident in all those that died and Salmonella choleraesuis was consistently isolated from their faeces and liver. In a further experiment at I ppm och ratoxin A in animals immunised against S. choleraesuis haemorrhagic diarrho ea resulted instead, associated with Serpulina hyodysenteriae and Campyloba cter coli. There was concomitant evidence of immunosuppression and delayed response to immunization. For the first time, susceptibility to natural inf ectious disease has been demonstrated in pigs exposed to the immunotoxicity of ochratoxin A. Differentiation of biochemical and histological changes a ttributable to ochratoxicosis or to secondary disease may require reinterpr etation of a classical description of experimental porcine ochratoxicosis.