JOINT-ILL has historically been a major economic drain on Scottish sheep farms, not the least of which is the added cost of treatment.

The disease, more properly known as infectious polyarthritis, causes extra time to be spent on gathering for treatment, while affected lambs do not grow well and some with a chronic joint infection can even be condemned at slaughter.


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

This bacteria enters the blood stream from the upper respiratory tract, tonsil, while it's old name of navel-ill, ie via an untreated umbilicus (navel), is not regarded as an important source. The bacteria then travel from the bloodstream to joint(s).


Moderate (4/10) to non-weight-bearing (10/10).

Lame lambs spend long periods in sternal recumbency.

Lambs reluctant to follow their dam.

Signs appear from five to 10 day-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).


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; or delayed swayback.


Diagnosis of an infected joint is based upon clinical findings


Post-mortem examination.


Procaine penicillin is the drug of choice for S dysgalactiae and E rhusiopathiae, which are responsible for over 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.

Non-steroidal anti-inflammatory drugs (NSAIDs) as directed by your vet.


Ensure timely adequate passive antibody transfer and reduce the environmental bacterial challenge by good hygiene;

Also, you can 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. Administering procaine penicillin to all lambs at 36 to 48 hours-old is very effective in the face of a disease outbreak of streptococcus dysgalactiae polyarthritis in the UK, but raises many concerns about indiscriminate antibiotic usage.


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 at slaughter of those lambs which show only mild lameness but have chronic joint swellings caused by fibrosis of the joint capsule.


Polyarthritis is a welfare concern in those lambs which do not respond to antibiotics. Lame lambs which do not recover after two courses must be euthanased for welfare reasons.

Further antibiotic therapy will not work and affected sheep should be destroyed.