Pathomorphology und microbiology of the urogenital tract of reproductively failed sows with positive deoxynivalenol result

OBJECTIVE Deoxynivalenol (DON) is a mycotoxin produced by fungi of Fusarium spp. It causes vomiting, but also exerts immunosuppressive effects that may be seen at local level e. g. the urogenital tract, in which case these effects are of relevance for fertility. The presented report describes a DON-associated pathomorphological picture of the urogenital tract in conjunction with the associated microbiological colonization. MATERIAL AND METHODS A total of 19 genital tracts (vagina, cervix, uterus, oviducts and ovaries) including the urinary bladder (n = 15) from reproductively failed gilts and different parity sows submitted from 8 farms in 2019/20 were examined pathomorphologically. DON as well as zearalenone (ZEA) were determined by using high performance liquid chromatography in 11 individual and 2 pooled (2 and 4 animals, respectively) bile samples. Microbiologic examinations of uterine (n = 17) and bladder (n = 12) specimens were additionally performed. RESULTS Nearly all vaginas (n = 16), cervixes (n = 15), uteri (n = 18) and numerous oviducts (n = 11) as well as urinary bladders (n = 11) displayed a mostly medium to severe chronical inflammation. In 17 cases, ≥ 2 organs were affected. Microbiologic evaluation revealed a usually mixed flora of several gram-negative and gram-positive bacterial species with E. coli, Streptococcus spp., Aeromonas spp. and Enterococcus spp. being the predominant species. A total of 8 individual and both pooled bile samples were found DON-positive (75.5 to > 200.0 µg/l). In a subset of the DON-positive samples, ZEA was simultaneously detected at low concentrations (6.57-21.20 µg/l). CONCLUSION AND CLINICAL RELEVANCE The results of the present study allow for the postulation that DON may cause fertility problems. Subsequent pathomorphological examinations of genital organs and the urinary bladder are recommended. When ≥ 2 organs are chronically inflamed and the uteri are additionally microbiologically positive, a contribution of DON may be assumed and confirmation via bile analysis is warranted.