Bacterial infections of the endometrium (the superficial layer of cells lining the uterus) are an important cause of conception failure.
Treatment often involves local administration of antibacterial agents directly into the uterus.
Potentiated sulphonamide drug combinations, such as sulfadiazine and trimethoprim, are commonly used in equine practice. They have a broad spectrum of activity and are well distributed throughout the body tissues.
Could oral administration of a suspension of sulfadiazine and trimethoprim (SDT) have a place in the treatment of bacterial endometritis?
Studies at the School of Veterinary Medicine, Louisiana State University, Baton Rouge, looked at the concentration of SDT in both the blood and endometrium of healthy, in season, mares after the administration of an oral suspension of sulfadiazine and trimethoprim.
Mares were treated five times at twelve hourly intervals. Blood was collected to monitor the concentration of SDT during the study and an endometrial biopsy was taken after sixty hours to measure the SDT concentration in the endometrium.
The Minimum Inhibitory Concentration (MIC) is the lowest concentration of an antibiotic that inhibits the growth of a given strain of bacteria.
The research, led by Gabriel Davolli, found that, after five consecutive treatments, the sulfadiazine and trimethoprim reached concentrations in the endometrium above the MIC – and so likely to be effective -for pathogens (such as Streptococcus equi zooepidemicus and Escherichia coli) that are commonly involved in uterine infections.
The work is reported in the Journal of Equine Veterinary Science.
The authors conclude: “the oral suspension of sulfazdiazine-trimethoprim should be an efficacious and viable treatment for bacterial endometritis.”
For more details, see:
Concentrations of Sulfadiazine and Trimethoprim in Blood and Endometrium of Mares After Administration of an Oral Suspension
Gabriel M.Davolli, Kelli N.Beavers, Victor Medina, Jennifer L.Sones, Carlos R.F.Pinto, Dale L.Paccamonti, Robert C.Causey
Journal of Equine Veterinary Science (2018) 67:27-30