Use of hyperimmune serum in treatment of endometritis in mares

Endometritis was induced in four progesterone-treated ovariectomized mares and in two seasonally anestrous mares by intrauterine infusion of Streptococcus zooepidemicus. The bacteria were suspended in phosphate buffered saline (PBS), or in nonimmune or hyperimmune serum. Uterine lavage was performed after 24 h. Significantly fewer (P < 0.05) bacteria were recovered from mares which received hyperimmune serum than from mares which received nonimmune serum or PBS. There was no significant difference between treatment with nonimmune serum or PBS. It is therefore suggested that increasing the availability of specific antibody reduced the severity of intrauterine infection.