WHILE lambing outdoors can help, there are still incidences of joint ill to contend with. Here, the National Animal Disease Information Service (NADIS), gives it's quick guide on how to spot the disease – which is also known as infectious polyarthritis – and how to contend with it.


• Localisation of bacteria within joint(s) to cause an infectious arthritis with moderate to severe lameness.

• Bacteria enters the blood stream from the upper respiratory tract, tonsil.

• The untreated umbilicus (navel) is not an important source.

• Bacteria travel from the bloodstream to joint(s).

Economic implications:

Lame lambs do not grow well and marketing is delayed by at least several months. Reaction in the drainage lymph nodes may result in condemnation of those lambs which show only mild lameness but have chronic joint swellings caused by fibrosis of the joint capsule.

• It is a major economic problem on many sheep farms.

• Cost of treatments.

• Extra time gathering sheep for treatment.

• Lambs do not grow well and are frequently culled.

• Condemnation of lambs which show only mild lameness but have chronic joint infection causing lymph node reaction.

Welfare implications:

Polyarthritis is a major welfare concern in those lambs which do not respond to antibiotic therapy and lame lambs which do not recover after two treatment courses must be euthanased for welfare reasons.

Further antibiotic therapy will not influence the joint pathology that is associated with such chronic infections and affected sheep should be destroyed for welfare reasons.

Clinical signs:

• Moderate (4 out of 10) to non-weight-bearing (10 out of 10).

• Lame lambs spend long periods in sternal recumbency.

• Lambs reluctant to follow their dam.

• Signs appear from five to 10 days-old.

• Fetlock and carpus affected more than other joints.

• Affected joint(s) are swollen, hot, and painful.

• Considerable muscle wastage over the affected leg(s).

Differential diagnoses:

Your veterinary surgeon may also consider the following diseases:

• Foot abscess or interdigital lesion.

• Cellulitis following dog bites.

• Fracture of a long bone.

• Muscular dystrophy.

• Delayed swayback.


• Diagnosis of an infected joint is based upon clinical findings.

• Arthrocentesis.

• Post-mortem examination.


• Procaine penicillin is the drug of choice for S dysgalactiae and E rhusiopathiae, which are responsible for more than 90% of joint ill cases.

• Penicillin injected once daily for at least five consecutive days.

• Administered during the early stages of lameness penicillin will effect a good cure.

• NSAID (anti-inflammatories) as directed by your veterinary surgeon.

Management measures:

• Ensure timely adequate passive antibody transfer.

• Reducing environmental bacterial challenge by good hygiene.

• Immerse umbilicus (navel) in strong veterinary iodine BP within the first 15 minutes of life and repeated at least once, two to four hours later.

• Procaine penicillin to all lambs at 36 to 48 hours-old is effective in the face of a disease outbreak of streptococcus dysgalactiae polyarthritis in the UK but raises many concerns about indiscriminate antibiotic usage.

* The aim of NADIS is to highlight the importance of better animal health through veterinary health planning and to encourage dialogue between farmers/livestock handlers and their veterinary practitioner. It provides a valuable learning resource and revision guide for everyone interested in animal health and welfare – see at www.nadis.org.uk