HEMATOLOGICAL, BIOCHEMICAL AND TOXICOLOGICAL INVESTIGATIONS IN SPONTANEOUS CASES WITH DIFFERENT FREQUENCY OF PORCINE NEPHROPATHY IN BULGARIA

Haematological, biochemical and toxicological investigations of blood and urine of normally slaughtered pigs exhibiting different frequency (1-2%, 10-20% and 50-60%) oi changes characterized as ''enlarged mottl ed kidneys''; at the slaughtering meat inspection were carried out to elucidate the nature of nephropathies encountered in Bulgaria. A conte nt of ochratoxin A, higher in the spring than the autumn, was found in the serum and urine samples. The mean contamination levels of ochrato xin A in consumed feeds ranged from 114 +/- 36 ppb for 1994 to 207 +/- 65 ppb for 1993. The renal changes were characterized by impairment o f proximal tubular function (indicated by an increased urinary excreti on of glucose and protein) as well as by decreased specific gravity an d increased pH in the urine mainly in pigs with 50-60% frequency of ne phropathy. The concentration of urea, creatinine and glucose in the bl ood was increased, whereas the serum protein and cholesterol were decr eased in pigs with 10-20% and 50-60% frequency of nephropathy. The mea n enzyme levels of gamma-glutamyl transpeptidase and leucine aminopept idase were significantly increased in the urine. The presence of granu lar casts and necrotic renal tubular cells were established in the sed iment.