The horse abdominal pathologies often needs surgical techniques to your complete resolution. This kind of procedure, usually a big trauma plus the anesthetic stress very important in horses, bring important systemic changes. At this work were evaluated the changes in blood constituents (cells and other components) generated by standing laparotomies followed by small colon enterotomies. The approach was made in left flank after sedation of horses with romifidine clorhidrate (80 mg.kg-1 , intravenously). The incision line in abdominal wall was infiltrated with 2% lidocaine in two different deep layers. The lateral thoracic nerve was blockade with 2% lidocaine too. The enteromies were made in ant mesenteric band of small colon. After exposition of intestinal loop, enterotomy and suture, the viscera was replaced to abdominal cavity, following the wall suture. The venous blood samples were obtained immediately before the surgical intervention and each subsequent 24 hours, for 3 days. The cell count used erythrocytes, leucocytes, basto neutrophyls and packed cell volume. The plasmatic concentration of protein, fibrinogen and hemoglobin were measured too. Variations in erythrocytes and hemoglobin results in an arise with statistic significance. The values of protein and fibrinogen as well leucocytes and bastoned neutrophils showed statistic differences. It was concluded that the cells and other values changed in a way to demonstrate an acute inflammatory pathology, compatible with an infectious syndrome, however without match with clinical status of healthy showed by horses.