The keeping of companion chicken flocks has recently grown in popularity, increasing the demand for advanced veterinary care. The clinical utility of echocardiography is currently limited by a lack of established reference intervals for adult chickens of non-commercial breeds. Therefore, the objective of this prospective observational study was to establish echocardiographic reference intervals for adult chickens of non-commercial breeds. Healthy adult chickens (n = 126) of both sexes and variou