14 February 1997

Joint ill threat hitting lambs

LAMBS face an new joint ill threat from the streptococcus organism.

The bacteria – Streptococcus dysgalactiae – is usually associated with mastitis in dairy cattle, but has been the cause of an increasing proportion of joint ill cases, says Scottish Agricultural College vet Graham Baird.

"Streptococcus has rarely been a cause of joint ill in the past, but anecdotal evidence suggests that the number of cases has increased over the last couple of years. Its not an enormous problem, but can affect a high proportion of lambs in afflicted flocks."

The infection shows with typical joint ill symptoms. Lambs may be reluctant to follow their mothers, then become lame, developing swollen, stiff, pus-filled joints, says David Strachan, SAC Aberdeen vet investigation officer.

"Depending on the vet, producers have tried to minimise infection risk by dosing lambs at birth with antibiotics – penicillin or penicillin-type – either orally or injected."

This injection should provide some protection, as lambs seem to be affected soon after birth. "The bacteria occurs everywhere – and it is carried on the ewes fleece, and even in her milk, without causing mastitis,"says Dr Strachan.

"Good hygiene at lambing will help reduce risks. But to reduce them further we really need to know more about the bacteria."