Description:
<jats:p>After several thousand sheep had been imported from Australia and New Zealand to Croatia during 1995, many native sheep that had been in contact with the imported animals acquired a severe ocular disease closely resembling infectious keratoconjunctivitis. In affected flocks glucose‐fermenting mycoplasma were isolated from 48 per cent of conjunctival swabs and <jats:italic>Branhamela ovis</jats:italic> from 58 per cent. Twelve of 42 culturally and biochemically identical isolates were identified as <jats:italic>Mycoplasma conjunctivae</jats:italic> by polymerase chain reaction. From the conjunctivae of two animals <jats:italic>M conjunctivae</jats:italic> and <jats:italic>M arginini</jats:italic> were isolated in mixed culture. For many reasons most farmers removed the imported animals from their flocks and only sporadic cases of the disease were recognised in 1996. At the end of 1997, six flocks which were clinically free of the disease but had been affected during 1995, and five flocks with no history of the severe ocular disease were examined clinically and microbiologically, and were found to be free of <jats:italic>M conjunctivae</jats:italic> infection. At the time, <jats:italic>B ovis</jats:italic> was cultured almost exclusively from sheep originating from flocks which had been affected during 1995 and/or 1996. It was usually isolated in pure culture or as the predominant bacterial species, and was often accompanied by mild conjunctivitis. There were no microbiologically confirmed new cases of infectious keratoconjunctivitis during 1998 and 1999.</jats:p>