Clinical, haematological and blood biochemical changes in goats after experimental infection with tick-borne fever

Abstract

Tick-borne fever in goats caused by Ehrlichia (Cytoecetes) phagocytophila was characterised by high fever, dullness, anorexia, tachycardia and a slight to moderate inhibition of rumen motility. The animals developed a gradual decline in the total number of circulating white blood cells. There was a decrease in lymphocytes over a short period, followed by an increase. The number of neutrophils was higher on the 3rd day, causing considerable change in the lymphocyte:neutrophil ratios. The number of eosinophils increased slightly. Serum alkaline phosphatase (ALP) decreased during the febrile episodes, and a marked decline was observed in both plasma zinc and iron concentrations. Furthermore, there was a small but progressive decrease of haemoglobin and haematocrit values. Circulating endogenous pyrogen/leucocyte endogenous mediator could not be detected in plasma from febrile goats. Tick-borne fever was passively transmitted to kids with plasma obtained from these febrile animals.