Bovine borreliosis: comparison of simple methods for detection of the spirochaete in the blood.

Natural Borrelia infection occurring in a calf was followed up using stained blood and buffy coat smears and direct observation of blood and buffy coat in order to compare these spirochaete detection methods. Direct examination of the platelet-plasma interface of the microhaematocrit capillary tubes after centrifugation allowed detection of two parasitaemias that were not seen in Giemsa stained blood smears. An ascending Babesia bigemina infection seemed to suppress the Borrelia parasitaemia. Spirochaetes were detected in five out of 37 Boophilus decoloratus ticks recovered from the infected calf. The blood and the haemolymph stages of Borrelia were measured. After treatment with oxytetracycline the spirochaete could no longer be detected.