Acute phase proteins in grass sickness (equine dysautonomia)

Abstract

Four acute phase proteins were assayed in the serum of normal horses and those with acute, subacute and chronic grass sickness, colic and inflammatory conditions, in order to investigate their diagnostic value in grass sickness. The grass sickness and inflammation group had a significantly increased haptoglobin concentration (P<0·01-P<0·001). Orosomucoid was elevated in acute, subacute and chronic grass sickness and inflammation (P<0·001, P<0·001, P<0·05 and P<0·05, respectively). Highest concentrations of haptoglobin and orosomucoid were recorded in subacute grass sickness. Ceruloplasmin was significantly higher in acute grass sickness cases than all other groups except the colic group (P<0·05-P<0·01). α2-macroglobulin was significantly higher in acute grass sickness than normal, colic and chronic grass sickness cases (P<0·01, P<0·05 and P<0·05). The time scale of changes suggests that the stimulus to haptoglobin and orosomucoid synthesis occurs at the onset of clinical signs whereas the increase in ceruloplasmin and α2-macroglobulin is more likely to reflect haemoconcentration.