Resumen de Tickborne diseases: Intercurrent tickborne fever infection and Bibersteinia trehalosi septicaemia in a five-week-old lamb

Roger Daniel, Kate Pugh, Nick Torrens, Amanda Carson, Mark Wessels

• 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 findings included a spleen that was approximately three times the normal size, with fibrin tags attached to the splenic capsule. All lymph nodes were grossly enlarged, oedematous, and dark purple in colour, particularly the mediastinal and bronchial lymph nodes. The lungs were uniformly dark pink in colour and had a firm rubbery texture. Bacteriological examination of mediastinal lymph node and spleen produced a profuse pure growth of Bibersteinia trehalosi.....