2023-05-082022-06-022023-05-082022-01-14http://repositorio.ifam.edu.br/jspui/handle/4321/1182Pyometra is defined as a uterine infection associated with bacterial interaction that especially affects older to adult dogs. This condition is considered one of the main pathologies of the reproductive system routinely observed in clinical medicine and in small animal surgery. The canine species is more affected when compared to its incidence in felines. This happens due to the specificity of the estrous cycle of dogs in which it presents prolonged stage intervals, especially when it comes to the diestrus phase, which can last an average of sixty days. Therefore, the endometrium remains under hormonal stimulation and its modifications for a significant time. The etiopathology and mechanisms involved in the emergence of this disease are not fully elucidated by the scientific community. However, the hormonal influence during numerous reproductive cycles has been considered the main triggering agent for the development of pyometra. In addition, we can highlight that other predisposing factors are correlated to its emergence, for example: bitches with advanced age, prolonged or deregulated estrous cycles, history of pseudopregnancy and in cases of pyometra in young females, the erroneous administration of estrus inhibitors is a cause of its appearance. The objective of this work is to approach the main concepts of this pathology, as well as its etiology, clinical signs and therapeutic protocols. Keywords: estrous cycle, cystic endometrial hyperplasia, pathophysiology, reproductionAcesso Abertociclo estral, hiperplasia endometrial cística, fisiopatologia, reproduçãoCNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIATrabalho de Conclusão de Curso