The study aimed to describe the changes in clinical findings and serum levels of gastrin, pepsinogen and chloride (Cl) in dairy cattle with displacement of the abomasum (DA) from day 0 until day 30 after surgery and to evaluate their diagnostic and prognostic value in evaluation of the abomasal function. The study was conducted on DA cattle (n=25) belonging to dairy farms in Hokkaido area, Japan. Cows were examined and sampled at days 0 (surgery), 7 and 30. Based on blood β-hydroxybutyric acid (BHBA) at day 0, DA cows were classified into three categories; DA only (1.2 mmol/L), DA with subclinical ketosis (DA SCK: 1.2–2.4 mmol/L) and DA with clinical ketosis (DA CK: ≥2.5 mmol/L). All DA groups had higher serum gastrin than their physiological reference values in cattle both before or after surgery. Serum gastrin was significantly increased (P0.05) in DA and DA SCK groups particularly at day 30 vs day 0. Serum pepsinogen and chlorides were not remarkably changed in any of the three diseased groups compared to reference values. Serum pepsinogen showed no significant within- and inter-group changes. The surgery and the 30-day follow-up period were not sufficient to serum gastrin to return to its physiological levels. In conclusion, further future studies may be required to investigate serum gastrin levels change in DA cattle. A longer follow up period up to 45 day is suggested.