Review on canine pyometra, oxidative stress and current trends in diagnostics

Pyometra is one of the most important and common disorders in canine. The disease results in life threatening condition associated with septicemia and toxemia. The condition commonly occurs during luteal phase of estrous cycle, generally 4 weeks to 4 months of estrous cycle. The age, parity, breeds, administration of hormones are some predisposing factors of the condition. However, interaction between potentially pathogenic bacteria and hormonally primed uterus is believed to result in pyometra. The disease is initiated in the form of cystic endometrial hyperplasia, which later progresses into purulent uterine content following bacterial infection resulting in pyometra. The disturbance in antioxidant and pro-oxidant balance succeeding bacterial infection results in oxidative stress. The resultant stress further induces endometrial degeneration, immunosuppression and additionally aggravates the condition. An important clinical sign is malodorous, sanguineous or mucopurulent vaginal discharge with general symptoms such as vomiting, polyuria, polydipsia, depression, anorexia and occasionally fever. Till date, ultrasonography is the best diagnostic method while radiology and serological test are also helpful. Recently, the estimation of inflammatory mediators (acute phase proteins and prostaglandin metabolites) has appeared as marker for diagnosis of the pyometra. Determination of levels of inflammatory mediators has emerged as an important diagnostic method because it can be helpful in prognosis of the condition. The pyometra can be best treated by surgical manipulation (ovariohysterectomy); however, hormonal treatment can be given in less severe cases which aimed at reducing the effect of progesterone on the reproductive tract. Together, provision of antioxidants could be helpful in disease recovery along with the determined treatment. In this review, incidence, predisposing factors, etio-pathogenesis, oxidative stress associated with condition, diagnostic methods and treatment are discussed.