Intercurrent tickborne fever infection and Bibersteinia trehalosi septicaemia in a five-week-old lamb.

WE wish to report the findings of a postmortem examination carried out by the Wales Veterinary Science Centre (WVSC) at Aberystwyth. Lamb deaths began to occur, at a rate of one per day over a two-week period, in a 300-ewe flock grazing mountain pasture. A postmortem examination carried out at the local veterinary practice revealed a focal 3 cm diameter swelling on the spleen, and a lymphadenopathy affecting particularly the mesenteric lymph nodes. A test for clostridial toxins in small intestinal contents gave a negative result. A second lamb was then submitted to the WVSC.This was a well grown, five-week-old Welsh mountain lamb, which was found dead with no prior clinical signs. Postmortem …