Abstract
Background:
Recently, an increase in the synthesis of APPs was associated with acute infections and inflammation in rabbits.

Aim:
The purpose of this study was to identify biochemical and molecular markers in rabbits that could be used for the early diagnosis of diarrhea.

Method:
Fifty male White New Zealand rabbits with an average weight of 450-650 grams and an age of 6-8 weeks were chosen and then divided into two groups: group A, which served as a control and was not exposed to any infections, and group B, which was infected with Escherichia coli strain O26 through a single oral injection. After 1, 3, 7, 11, and 15 days, four rabbits from the control group and six rabbits from the infected group were slaughtered at various ages. For the purpose of determining the levels of hemoglobin (HP), C-reactive protein (CRP), and ceruloplasmin (CP) activity, as well as the electrophoresis patterns of proteins, serum samples were taken. For the purpose of determining the level of mRNA expression of hemoglobin, livers were utilized.

Results:
The results revealed a significant increase in HP, CRP concentration, and CP activity in all infected rabbits. Electrophoresis patterns indicated a decline in serum albumin levels and an increase in α2, β and γ-globulins levels post-infection. The mRNA expression of HP was significantly increased in infected rabbits.

Conclusion:
APP patterns and concentrations could be used as potent markers for the early detection of enteric disorders and diarrhea induced by E. coli infection in weaning rabbits.

Key words: Ceruloplasmin, C-reactive protein, Diarrhea, E. coli, Haptoglobin, Rabbits