EN
Spirochetes Brachyspira spp. are found in large intestines of humans and animals. The following pathogenic species of Brachyspira are involved in avian intestinal spirochaetosis (AIS): B. alvinipulli, B. pilosicoli, B. intermedia and B. hyodysenteriae. There are also unclassified spirochetes isolated from birds, which are known as B. pulli. AIS may cause significant economical losses in poultry production. AIS seems to be a fairly widespread problem in laying hens and captive rheas. Chronical infections with a mild course of the disease are difficult to diagnose and only limited data concerning the prevalence, controlling and prevention of AIS are available.