How long Does the Antibiotic Ceftiofur Remain Effective in the Uterus after Intrauterine Infusion in Both Healthy Mares and mares with a Uterine Infection? (13-12)


Camilla J. Scott, BVetMed, MRCVS, DACT
Ghislaine A. Dujovne, DVM, M.S., DACT
Bruce W. Christensen, DVM, M.S., DACT

Bacterial endometritis is a leading cause of infertility in the mare and a major cause of economic loss to the equine industry. The use of intrauterine ceftiofur to treat endometritis is common practice; however, its efficacy had not been evaluated, especially in clinical cases of endometritis. A primary question was how long the ceftiofur remained at an effective concentration following administration for successful targeting of the infection in both healthy mares and mares with a uterine infection. The study showed that endometrial tissue concentrations of ceftiofur in healthy mares were above the concentration required to target common uterine infections for the 48 hour testing period. But in infected mares, tissue concentrations of ceftiofur were only above target concentrations for Escherichia coli for 6 hours and Streptococcus zooepidemicus for 24 hours.


The results of this study suggest that healthy endometrial tissue retains target concentrations of ceftiofur for longer than inflamed tissue. In healthy mares, a prophylactic ceftiofur infusion would appear to be effective for at least 48 hours; however, in mares infected with S. zooepidemicus, a daily infusion protocol is required to avoid treatment failure. Knowing the length of time the antibiotic remains effective will provide veterinarians important information to design and implement treatment plans for their patients. Future studies to evaluate intrauterine antibiotic treatment for endometritis on mares with endometritis is a logical next step.