Gross pathological findings in sows of different parity , culled due to recurring swine urogenital disease ( SUGD ) in Kenya

BOMA, M.H. & BILKEI, G. 2006. Gross pathological findings in sows of different parity, culled due to recurring swine urogenital disease (SUGD) in Kenya. Onderstepoort Journal of Veterinary Research, 73:139–142 In a large Kenyan production unit the urogenital organs and mammary glands of 771 sows, culled due to recurring swine urogenital disease (SUGD) were subjected to necropsy Necropsy findings were analysed separately according to parity group of the sows [parities 2 (n = 252); 3–5 (n = 250); and > 5 (n = 269)]. Sows of higher parities had more pathological changes in their ovaries, uteri, vaginas, cervices, urinary bladders, kidneys and mammary glands compared to parity 2 sows (P < 0.05 and P < 0.01, respectively). Parity 2 sows had more ovarian degeneration, mucosal hyperaemia, congestion in the bladder, and acute purulent exudative mastitis than parity > 5 sows (P < 0.05 and P < 0.01, respectively).


INTRODUCTION
Swine urogenital diseases (SUGD) are often found in combination with mastitis metritis agalactia syndrome (MMA) (Waller, Bilkei & Cameron 2002) and may contribute to inferior litter size (Sanders & Bilkei 2004), inadequate lactation performance, lower farrowing rate (Thacker & Bilkei 2005), and abortion and sow mortality (D'Allaire & Drolet 1992).In a retrospective study (Bilkei, Bölcskei & Goos 1995), 101 sows that had been culled for reproductive failure, revealed gross pathological changes in the urinary bladder, urethra and mammary glands in all cases; 50 % also had uterine changes.In similar work (Bilkei & Goos 1994), 73 % of sows culled for reproductive failure were found to have inflammatory changes involving both the urogenital tract and the mammary glands.
The present retrospective study was performed in order to prove a relationship between pathological changes in different parts of the urogenital organs and mammary glands in a hot African climate in sows of different parity culled due to recurring SUGD.

MATERIAL AND METHODS
The trial was performed in a large Kenyan indoor production unit (2 239 sows) from August 2004 to August 2005.cervices, urinary bladders, renal pelves, and mammary glands were evaluated.
For the purpose of this study, the pathological examinations were performed according to the following criteria:

Ovaries
• Adhesions between oviduct and ovaries

RESULTS
Parity 2 sows had more ovarian degeneration than sows of higher parities, in which there were more adhesions between oviduct and ovaries, ovarial cysts, multiple tertiary follicles and regressed corpora lutea (P < 0.05 and P < 0.01, respectively).Sows of higher parities had more pathological changes in their uteri, vaginas, and cervices when compared to those sows of parity 2 (P < 0.05 and P < 0.01, respectively).With the exception of mucosal hyperaemia, congestion of the bladder mucosa, and acute purulent mastitis, parity > 5 sows had more pathological changes in the urinary bladder, renal pelves and mammary glands when compared to parity 2 sows (P < 0.05 and P < 0.01, respectively).
The present study indicates, that as a sow gets older, pathological changes in one part of the urogenital organs will be followed by pathological changes in other parts of the urogenital tract and mammary glands.Parity at culling markedly influences the economic well-being of a pig breeding unit (D'Allaire & Drolet 1992; Almond & Richards 1986).It has also been suggested that sows, which repeatedly suffer postparturient SUGD, should be culled for economic reasons before a decline in production takes place (Bilkei et al. 1995;Bilkei & Goos 1994).Biksi, Takacs, Vetesi, Fodor, Szenci & Fenyö (2002) examined the urogenital organs of 499 sows and found that animals suffering from "urocystitis" were 3.5 times more likely to have endometritis than animals without "urocystitis".
The breakdown of uterine tissue provides a medium that favours the growth of a variety of opportunistic microorganisms originating from the urinary bladder and/or vestibulum vaginae (Dial et al. 1992;Sanders & Bilkei 2004).Retention of remnants of the placenta may predispose sows to mild metritis and endometritis (Biksi et al. 2002).In addition, the reproductive tract of sows is susceptible to infection after farrowing because of the periparturient increase in the number of both apathogenic microflora and facultative pathogens in the caudal vagina and urinary bladder (Bilkei et al. 1994).While most bacteria are eliminated within 12-30 h after delivery, facultative pathogens may overgrow non-pathogenic microflora and establish mildly invasive endometritis (Bilkei et al. 1994).Biksi et al. (2002) stated that the sensitivity of macroscopic examination methods was not higher than 18.1 % in cases of endometritis and 47.9 % in cases of "urocyst itis", while the sensitivity of bacteriology for the diagnosis of the same conditions was only 31.8 % and 63.0 %, respectively.Similar to the present findings, Biksi et al. (2002) found that a large proportion of ani mals that they had examined did not show inflammatory lesions.
The recovery from postpartal SUGD is influenced by many factors, including the hormonal status of the sow, and local immunity, and possibly by reduced leukocyte activity and delayed immune response of the postpartum uterus (Bilkei & Goos 1994).Stress, outdoor production, and an unsatisfactory hygienic environment might trigger SUGD in the postparturient sow (Thacker & Bilkei 2005).
The results of this study indicate that sows having suffering from recurring postparturient urogenital diseases should be culled for economic reasons before the manifestation of low reproductive production level.

TABLE 1
Gross pathological findings in urogenital organs and mammary glands in sows of different parity, culled due to urogenital infections in their previous history (number and percentage of cases in a parity group