At lambing time there are a number of things that can result in the mortality of newborn lambs. These include watery mouth, umbilical infection and Joint ill.

Joint ill (Infectious polyarthritis)

This is a bacterial joint infection of young lambs in the first four weeks of life. The result is infectious arthritis which leads to lameness. Joints are swollen, hot and painful, ultimately this causes muscle wastage and lambs will struggle to thrive. The number of joints affected by Joint ill vary from one to four, the most common is the knee (carpus), but it can also affect the hock, fetlock and stifle joints.

Lambs become infected through bacteria spreading through the bloodstream in newborn lambs, this can be through the gut, upper airway, tonsils and untreated navals. The disease can be present in both indoor and outdoor systems, however ultimately unhygienic conditions, including dirty housing or insufficient colostrum intake increase the risk.


If you suspect joint ill is present the best course of action is to consult you vet who can provide advice of the best course of treatment.

Reducing the risk

The bacteria that causes joint ill can survive well in dry and damp straw and soil, this can cause the bacteria to build up increasing the risk to your flock. To try and reduce the risk you can:

·        Lower bacterial risk

·        Clean environment

·        Ensure each lamb has sufficient colostrum

·        Naval Treatment

 AHDB have provided some more details, which you can view here : Treating joint-ill at lambing: getting it right | AHDB