Jaundice and Mycoplasma ovis in Australian sheep

Abstract

Mycoplasma ovis has been known to infect Australian sheep for >60 years. The infection can induce haemolytic anaemia with associated ill-thrift and occasionally mortality. The haemolysis can also lead to jaundice in subclinically infected sheep sent for slaughter. Jaundiced lamb and sheep carcases are condemned in Australian abattoirs, with no attempt to determine, nor records kept of, the aetiologies of these condemnations. It is assumed that the jaundice is caused either by plant toxin-induced liver damage, severe haemolysis due to chronic copper toxicity or M. ovis infection. M. ovis is globally prevalent and various genotypes have been described, but there has not yet been a phylogenetic analysis of the organism in Australia. Large-scale antimicrobial treatment in an extensive production setting is not considered feasible. Convincing economic data in support of a concerted effort to prevent the disease have not yet been presented, but its zoonotic potential might prompt a OneHealth approach.