Pyometra in bitches induces elevated plasma endotoxin and prostaglandin F2alpha metabolite levels

Abstract

Endotoxemia in bitches with pyometra can cause severe systemic effects directly or via the release of inflammatory mediators. Plasma endotoxin concentrations were measured in ten bitches suffering from pyometra with moderately to severely deteriorated general condition, and in nine bitches admitted to surgery for non-infectious reasons. Endotoxin samples were taken on five occasions before, during and after surgery. In addition, urine and uterine bacteriology was performed and hematological, blood biochemical parameters, prostaglandin F2alpha metabolite 15-ketodihydro-PGF2alpha (PG-metabolite), progesterone and oestradiol (E2-17beta) levels were analysed. The results confirm significantly increased plasma levels of endotoxin in bitches with pyometra and support previous reports of endotoxin involvement in the pathogenesis of the disease. Plasma concentrations of PG-metabolite were elevated in pyometra bitches and provide a good indicator of endotoxin release since the concentrations were significantly correlated to the endotoxin levels and many other hematological and chemistry parameters. The gamma-globulin serum protein electrophoresis fraction and analysis of PG-metabolite can be valuable in the diagnosis of endotoxin involvement if a reliable, rapid and cost-effective test for PG-metabolite analysis becomes readily available in the future. Treatment inhibiting prostaglandin biosynthesis and related compounds could be beneficial for bitches suffering from pyometra.

Figure 1

Plasma endotoxin levels in the control group and the pyometra bitches measured at five different sampling occasions; ET 1 = before general anaesthesia, ET 2 = during skin incision, ET 3 = after removal of the uterus/major part of the surgical procedure, ET 4 = during skin suturing, ET 5 = the day after surgery, ET X = mean endotoxin levels of all sampling occasions. Error bars represent 1 SE of the mean. The endotoxin levels were significantly (P < 0.05) higher in the pyometra bitches for sampling occasion ET 3, ET 4 and also for ET X.

Figure 2

Significantly (P < 0.05) higher concentrations of 15-ketodihydro-PGF_2α-metabolite (PG-metabolite) were measured in plasma sampled before surgery in the pyometra group compared with control bitches. Error bars represent 1 SE of the mean.