Caseous Lymphadenitis in Sheep and Goats: A Chronic Welfare and Management Challenge

CLA causes chronic abscess formation in lymph nodes causing pain, production loss, and significant welfare impact across affected flocks.

Key Facts

Caseous lymphadenitis is caused by Corynebacterium pseudotuberculosis, spread by pus from ruptured abscesses
External abscesses appear as fluctuant swellings under the skin at lymph node locations
Internal abscesses on lymph nodes of the lungs and liver cause chronic weight loss and production decline
The disease is endemic in many sheep and goat populations worldwide with 10-70% prevalence in affected flocks
No reliable cure exists - affected animals carry infection for life
Vaccination is available in some countries and reduces incidence
A test-and-cull strategy with ELISA serology can reduce herd prevalence over time

Welfare Considerations

CLA causes chronic welfare compromise in affected animals - internal abscesses cause progressive weight loss, reduced production, and in advanced cases, respiratory compromise from pulmonary involvement. Affected animals often look outwardly normal until disease is advanced, masking significant internal suffering. External abscesses cause local pain and the risk of rupture with subsequent environmental contamination. Test-and-cull programs systematically reduce the proportion of animals suffering from this disease across the flock over time, representing a genuine improvement in herd welfare.

What You Can Do

Implement a test-and-cull program using ELISA serology to identify and remove infected animals
Vaccinate in countries where CLA vaccines are licensed to reduce new infections
Manage ruptured abscesses carefully - collect and dispose of pus to prevent environmental spread
Wear gloves when handling suspected CLA cases - the organism can cause skin infections in humans
Screen purchased animals for CLA before introduction to clean flocks
Monitor body condition and production as indicators of internal CLA progression
Work with your vet to develop a CLA management plan appropriate for your flock's prevalence