Pyometra in the mare
Hughes, J.P.; Stabenfeldt, G.H.; Kindahl, H.; Kennedy, P.C.; Edqvist, L.E.; Neely, D.P.; Schalm, O.W.
Journal of Reproduction and Fertility. Supplement 1979(27): 321-329
1979
ISSN/ISBN: 0449-3087 PMID: 289805 Document Number: 153847
Spontaneous, chronic pyometra in 16 mares was not associated with clinical signs of systemic disease. Pus varied in quantity and character between mares, and within the same mare, over long periods of time. Single or multiple isolations of bacteria were usually obtained on culture of the pus, but occasionally culture results were negative. Blood total leukocyte counts were usually within (but occasionally below) the low normal range as a result of neutropenia which was sometimes accompanied by lymphopenia. Monocytes and eosinophils, within the normal ranges initially, increased progressively with time. There was a tendency for mild suppression of erythropoiesis which led to normocytic-normochronic anaemia in some animals. All of the mares had endometritis, but the type and its severity varied among animals, and between different areas of the same uterus. The least endometrial damage was present in mares with shortened oestrous cycles involving premature release of PGF-2 alpha and consequent corpus luteum regression. More severe endometrial damage was associated with lengthening of the oestrous cycle resulting from prolonged luteal activity due to delayed or inadequate PGF release. In a few animals, there was a complete loss of cyclic luteal function, the longest continuous luteal phase observed being 613 days; no cyclic PGF release patterns were observed in these animals.