Contagious ovine digital dermatitis (CODD) - where are we now?

Contagious ovine digital dermatitis (CODD) is a cause of severe lameness in sheep in the UK and Ireland with cases now apparently occurring elsewhere in the world. Disease commences at the coronary band as an erosive/ulcerative dermatitis progressing to underrunning of the hoof horn capsule which may lead to its evulsion. The disease is strongly associated with spirochaetes identified as Treponema medium, Treponema phagedenis and Treponema pedis; which are also associated with other skin diseases including bovine digital deramatitis. Key risk factors for sheep developing CODD have recently been identified and these include co-infection with footrot, poached pasture and larger flocks. There appears to also be a seasonal effect with increases in flock prevalence observed in spring and late summer. Control is focused on controlling risk factors, especially footrot, treating affected individuals with an appropriate antimicrobial, isolating affected individuals and adopting good biosecurity practices. Buying in infected sheep is considered by farmers to be the biggest risk to introducing CODD to a flock and it is recommended to turn over all sheep on entry and inspect all feet to try and limit this risk. CODD may be clinically eliminated from flocks, but a whole flock metaphylactic approach using antimicrobials is not recommended.