Polyarthritis caused by Erysipelothrix rhusiopathiae in three Austrian sheep flocks - diagnosis, treatment and management measures.

Polyarthritis caused by Erysipelothrix rhusiopathiae is a well-known disease in pigs, and ovine erysipelas infection also commonly affects two-to-six month-old lambs. This report describes case histories of three sheep flocks where lambs exhibited swollen joints and lameness. Special emphasis was given to clinical and diagnostic imaging findings, synovia sampling and the treatment regime. Lambs with only mild lameness, liquid serofibrinous joint effusion and lambs showing no bone involvement, as revealed by ultrasonography or radiography, were treated with systemically administered antibiotics selected from results of antimicrobial susceptibility testing of E. rhusiopathiae isolated from synovial samples, and non-steroidal anti-inflammatory drugs. Lambs with severe lameness and severely swollen joints were euthanized, and routine necropsy was undertaken with a focus on the joints. Further, a herd-specific autogenous vaccine was produced by a specialized laboratory. In conclusion, E. rhusiopathiae infection should be considered as a differential diagnosis in herds associated with lameness and polyarthritis in lambs aged between two up to 17 months.