Influence of chlorhexidine on seminal patterns in stallions

Ejaculates were collected at 3-day intervals before, during and after a washing procedure with chlorhexidine (2%). Semen motility and pathology were determined before and after deep-freezing. Blood samples were taken before and within 1 h after washing procedures and then extracted in ether. This was followed by HPL chromatography. Chlorhexidine concentrations in blood and seminal plasma were distinctly higher in the treated stallions than in control groups. Concentrations in the control groups were below the detection limit of the column. Significant correlations between decreasing semen quality (% immotile cells, % morphological aberrations) and chlorhexidine treatment were found. A change of the present requirements for imports into North America should be considered to improve the semen quality of deep-frozen ejaculates.