Cheesy gland, or caseous lymphadenitis (CLA), is an infection of sheep and goats caused by the bacterium Corynebacterium pseudotuberculosis.
Flock infection is widespread but does not cause serious production losses on farm. However, it is a major cause of economic loss to the meat industry due to condemnations and carcase trimming.
Conditions when cheesy gland is likely to occur
- animals have not been vaccinated
- after shearing as the bacteria can gain access either through shearing cuts or directly through freshly shorn skin. Bacteria can be spread on shearing equipment
- dipping sheep immediately after shearing
- rubbing and contamination of wounds and broken skin when animals are in close contact. This can be direct contact between animals or via contact with contaminated surfaces
- small yards, direct physical contact and close grazing of contaminated grass or feed in feed troughs.
Identification and diagnosis
Abscesses develop in lymph nodes anywhere in the body and may be obvious in freshly shorn sheep. Sometimes sheep and goats will cough if abscesses are in the lungs.
Abattoirs will also identify the presence of cheesy gland in their carcase feedback.
An integrated approach to prevent cheesy gland should consider the following:
- vaccinating all animals in the flock, except lambs sold as suckers. Sucker lambs do not need vaccinating because they are sold before abscesses develop. When vaccinating, follow the directions on the vaccine label
- ensuring proper dipping hygiene and only dip sheep if attempting to eradicate lice
- shearing sheep carefully to prevent shearing cuts and do not dip until cuts have healed.