Suspected Lyme borreliosis in sheep.

Two cases of suspected Lyme borreliosis in lambs are described. The clinical signs observed resemble those described for Lyme borreliosis in dogs and horses. The lambs were approximately six months old and came from two different flocks in a district heavily infested with Ixodes ricinus ticks. The lambs had pronounced lameness in one leg, generally bad condition and poor appetite. They had high serum levels of IgG antibodies to Borrelia burgdorferi when tested in an ELISA. The other lambs in the flocks were negative to B burgdorferi antibodies. Attempts were made to isolate spirochaetes from one of the lambs, but were unsuccessful.