Joint-Ill in Lambs

Joint-ill is a common disease of young lambs, up to one month old, in sheep flocks across the UK. The disease often impacts between 1 – 2% of lambs in a flock, but up to 50% has been reported.

The disease is characterised by an arthritic inflammation, usually of the limb joints, which results in lameness, ill thrift and in some cases death. Sometimes other joints can be affected, such as joints in the spine resulting in limb paralysis. The principal cause is a bacterial infection which localises to the joints. The most common species of bacteria isolated from infected joints is Streptococcus dysgalactiae. Only limited information is available on the routes of infection.

Infections associated with the umbilical cord, tail docking, castration and ear tagging wounds are all implicated as bacterial entry points, as well as via the lamb’s mouth. The presence of the bacteria in the lambing environment and the ewe’s vagina are both potential sources of infection. Treatment options are limited to antimicrobials and anti-inflammatory drugs often with limited success, resulting in the culling of severely affected lambs on welfare grounds.