EFFECT OF RANITIDINE ON INTRAGASTRIC PH IN CLINICALLY NORMAL NEONATALFOALS

Objective-To determine intragastric pH in newborn foals and to examine the effect of IV or oral administration of an H-2-receptor antagonist on intragastric pH. Design-Prospective controlled study. Animals-6 he althy mixed-breed neonatal foals. Procedure-lntragastric pH was measur ed, using an antimony electrode. Foals were monitored on days 2, 4, an d 6 after birth, and each received 3 treatments. The pH was recorded f or 4 hours before treatment and for 10 hours after ranitidine administ ration (2 mg/kg [0.91 mg/lb] of body weight, IV; 6.6 mg/kg [3 mg/lb], PO) or 20 hours after corn syrup administration. Mean and median pH an d percentage of time pH was greater than or equal to 4 were calculated . Results-Mean intragastric pH significantly increased for 5 hours aft er IV administration of ranitidine, compared with baseline data. Perce ntage of time intragastric pH was greater than or equal to 4 increased significantly for 4 hours after ranitidine administration, and median pH increased significantly for hours 2 to 4 after administration. Ora l administration of ranitidine significantly increased mean and median pH for hours 2 to 8 after administration and percentage of time pH wa s greater than or equal to 4 for hours 2 to 7 after administration. Cl inical Implications-Neonatal foals have highly acidic gastric fluid. I ntravenous or oral administration of ranitidine significantly increase d intragastric pH for 4 and 8 hours, respectively. Suckling affected i ntragastric pH and underscored the need for frequent feeding of neonat al foals.