SERUM AND SYNOVIAL CONCENTRATIONS OF PENICILLIN-G IN HORSES AFTER 2 DIFFERENT DOSE SCHEMES

It has been suggested that many equine pathogens may now be less susce ptible to penicillin G than in the past and may require higher minimum inhibitory concentrations. Because of this implication, a study was c onducted with 10 adult, clinically normal horses. Divided into two gro ups, the first group received a single dose of 80,000 IU/kg of sodium penicillin G (75%) and procaine penicillin G (25%) every day for 3 day s in a volume of 70 to 80 ml approximately, injected intramuscularly i n four different sites. The second group received 20,000 IU/kg of the same drug in the same four sites every 6 hours in similar volumes also for a period of 3 days, to equal a dose of 80,000 IU/kg/day. Comparis ons of the two groups were made and conclusions drawn.