RESUMEN
The purpose of this study was to evaluate the changes in the serum concentrations of haptoglobin [Hp], serum amyloid A [SAA] and IgG, IgA in calves with diarrhea caused by rotavirus, coronavirus, Escherichia coli F5 and Eimeria species. The experiment was carried out on 40 diarrhoeic and 10 non-diarrhoeic calves [group C]. A total of 13 calves were infected with rotavirus or coronavirus [group V], 12 calves with E. coli F5 [group B] and 15 calves with Eimeria species [group P]. SAA and Hp levels of calves in groups V, B and P were statistically higher than group C [P<0.05]. SAA and Hp levels of the group B and group P were significantly higher than the group V [P<0.05]. SAA and Hp levels in group B were not significantly higher than the group P. The levels of IgG and IgA were found to be lower in groups B and V compared to other groups. There was a negative correlation between immunoglobulins and the levels of serum Hp and SAA in groups B and V [r=-0.315 and r=-0.369, respectively, P<0.05]. Serum SAA, Hp, IgA and IgG levels could be useful for the diagnosis and differential diagnosis of diarrhea caused by rotavirus, coronavirus, E. coli F5 and Eimeria species