Abstract
The bacteriological examination of a faecal specimen from a 20-year-old female rhesus macaque (Macaca mulatta) with diarrhoeal illness revealed the presence of a large number of a relatively new enteric pathogen, Arcobacter butzleri. The animal was from a closed colony of about 60 females, some of them were showing intermittent diarrhoea possibly related to Giardia spp. Conditions for the isolation and identification of A. butzleri are reported, as well as discussions about its role as a primary pathogen and its zoonotic potential.