Concentrations of inflammatory markers and clinical findings in bitches surgically treated for pyometra in Khon Kaen, Thailand

Abstract: Pyometra is a common reproductive disease affecting intact bitches. The disease is defined by accumulation of purulent material within the uterus, and can potentially be life-threatening. Clinically, affected bitches can present with a variety of signs and diagnosis can be challenging in more indistinct cases. It is not uncommon that bitches with pyometra manifest systemic inflammatory response syndrome (SIRS) in response to the bacterial infection, i.e. sepsis. Rapid initiation of treatment is then necessary in order to prevent progression into hypotension and organ dysfunction, known as septic shock. If one or more organ systems fail entirely, death usually follows. Delay of effective antibiotic treatment after the onset of hypotension in patients diagnosed with septic shock has been shown to be a crucial therapeutic factor associated with mortality. Correct initiation of treatment is however complicated by the fact that it is diagnostically challenging to identify patients suffering from sepsis at an early stage. There is no gold standard to diagnose sepsis, since blood cultures may remain negative in 30-50 % of the patients and is not yet rapid enough. Clinical criteria used to detect SIRS in dogs include body temperature, heart rate, respiratory rate, white blood cell count and band neutrophils. These criteria are unspecific and when aiming for high sensitivity, the specificity decreased resulting in a relatively high proportion of dogs falsely diagnosed with SIRS. Consequently, there is a need for biomarkers to achieve effective diagnosis of sepsis in dogs, and make it possible to initiate necessary treatment at an early stage. This study investigates the possible use of albumin, iron and C-reactive protein (CRP) as adjunctive diagnostic markers for sepsis and prediction of prognosis measured as prolonged hospitalization. Nine dogs with pyometra and 15 healthy control dogs were included in this study. Blood samples were collected pre-operatively, 24 hours post-operatively and 7-10 days post-operatively. The serum was analysed in Sweden for concentrations of albumin, iron and CRP. Tissue samples were removed from the uteri of the dogs surgically treated for pyometra and embedded in paraffin in Thailand. The embedded samples were then histologically examined in Sweden. Blood cultures and bacterial swabs from the uteri were analysed for bacterial growth and isolated strains tested for antimicrobial sensitivity in Thailand. The results of this study showed that none of the investigated inflammatory markers differed between septic and non-septic bitches, which indicate that none of the investigated parameters have a potential clinical value for detection of sepsis. However, the number of dogs included in the study was low and a larger study material would be useful for further evaluation. Broad-spectrum antibiotics was used routinely in bitches treated surgically for pyometra and also in bitches admitted for elective spaying at Khon Kaen University Animal Hospital. Multiresistance could not be observed in any of the isolates from the uteri bacterial swabs, but a larger study material and a standard profile of antimicrobials tested would be beneficial to give a more correct interpretation of the antimicrobial susceptibility tests and to survey antibiotic resistance.