Some aspects of urogenital tract diseases of female breeding swine

Abstract

Reproductive failure accounts for substantial losses in the swine industry worldwide. Urogenital tract infections are among the most important causes of reproductive failure. Studies performed in the framework of this dissertation were directed to facilitate the understanding of some aspects of urinary tract disease in female breeding swine. Two studies were related to Actinobaculum suis, a "specific" urinary tract pathogen of swine. One other report was made on the prevalence of urogenital tract lesions in culled female breeding swine and the statistical and epidemiological associations between urocystitis and non-specific endometritis. An extensive literature survey on urogenital tract diseases of female breeding swine was made. Anatomy and physiology of the urinary and reproductive system, predisposing factors, pathogenesis, diagnosis, therapy and prevention of lower urinary and genital tract disorders, with particular references to urocystitis and non-specific endometritis were discussed in detail. The survey provided practical references to less often discussed subjects like economic importance of urogenital tract diseases, production data analysis, and herd inspection in relation to reproductive problem solving. It became apparent from the literature survey, that the putative predisposing effect of urocystitis to non-specific endometritis, although biologically plausible, is insufficiently backed by statistical analyses. Moreover, magnitude of such associations, and the effect of possible confounders were not discussed yet in the available literature. It also became apparent, that urogenital tract diseases of swine were not discussed yet in detail in the Hungarian scientific literature. Actinobaculum suis is widely indicated as a leading cause of urinary tract disease in female swine. However, its occurrence has not been reported previously in Hungary. In a study directed to prove the presence of Actinobaculum suis in Hungarian swine herds, we have isolated seven strains from preputial swab samples of boars in two farms and one from the urinary bladder of a sow having subacute haemorrhagic-necrotizing cystitis. This was the first isolation of A. suis in Hungary. We have also proven that A. suis is not a strictly anaerobic microorganism. Therapy of urogenital tract infections frequently utilizes different antimicrobials. Information on antibiotic sensitivity patterns of facultatively pathogenic bacteria of the urinary tract, and especially of Actinobaculum suis strains is quite limited. An in vitro study was performed to determine the antibiotic sensitivity of 12 Hungarian isolates of A. suis, with a special reference to novel antimicrobials. A comparison of disc diffusion and agar dilution methods was also made. Twenty one and twenty four antimicrobials were tested in the two methods, respectively. Sensitivity of all Hungarian strains was not different from the type strain, results yielded by the two methods were closely correlated. Some strains showed partially distinct resistance patterns. Based on the current literature recommendations and our in vitro results, where available, semisynthetic penicillines, ceftiofur, florfenicol, tetracyclines, and possibly some of the quinolones can be useful in treating urinary tract infections of swine involving A. suis. Slaughterchecks are integrated part of reproductive problem solving in many countries, including Hungary. Their use is especially indicated in cases of noninfectious reproductive failure and urogenital tract problems. Slaughterhouse sampling and subsequent detailed laboratory examination of urogenital tracts of sows and gilts culled for reproductive failure were performed in a study. 499 animals from 21 farms over a six-year period were sampled. We could conclude, that the prevalence of major urogenital tract lesions was similar to what reported in foreign studies. This was among the first detailed reports on the prevalence of urogenital tract lesions of sows and gilts in Hungary. A comparatively large set of data on macroscopical, histopathological and bacteriological results of sow and gilt urogenital organs was collected in a study described above. This dataset was subjected to a number of epidemiological analyses. We determined sensitivity and specificity of macroscopic and bacteriologic diagnosis of urocystitis and endometritis as compared to the results of histopathology (Gold Standard). Sensitivity of macroscopic and bacteriologic diagnoses appeared quite low. Thus, macroscopic or bacteriological examination of the urinary bladder or the uterus alone is likely to be not sufficient to arrive at a correct diagnosis of urocystitis or endometritis. Histology should be utilized whenever possible for establishing such a diagnosis. We have also examined whether the presence of urocystitis and endometritis are related when the effect of parity is accounted for. Our results indicated that urocystitis is indeed positively associated with endometritis, regardless of the parity of the animal. The odds ratio of approximately 3.5 indicated a strong positive association between these two conditions.