This study aimed to evaluate parameters of acid-base balance in horses submitted to an experimental model of intestinal obstruction. Twenty-four animals were divided in four groups: instrumented control (GI), duodenum obstruction (GII), ileum obstruction (GIII) and large colon obstruction (GIV). Venous blood samples were collected before surgery (T0), during the obstruction (T30ob-T180ob) and after unblocking procedures (T60des-T180des). Animals from GIV, at T30ob and animals from GII, at T60ob, T90ob and T120ob, presented higher values for pH(v), cHCO-3(vP) and cBase(v) which, added to the increase of pCO2(v) and ctCO2(v), characterized the metabolic alkalosis with respiratory compensation. At T90ob and T120ob, in GII animals, and at T180ob, in GIII animals the pO2(v) and sO2(v) had similar response. Low values presented by GII animals were associated to hypercapnia or hypoventilation triggered for metabolic alkalosis correction. However, a hypoxemia presented by GIII animals was associated to hypovolemia at that period. There were light and temporary acid-base alterations that are not capable to predict specific intestinal obstruction diagnosis in equines with colic. However they help in prognosis since both have a direct relation with the precociousness of gastrointestinal disturbance.
horse; blood gas analyses; intestinal obstruction
