Use of frozen semen in bitch

Frozen semen was first used successfully in the bitch in 1969. Initially semen was inseminated by vaginal insemination and subsequently, intrauterine techniques were used, achieving higher pregnancy rates than vaginal insemination. For optimal results with freezing and using frozen semen, careful collection, assessment, freezing and handling techniques must be employed. It is important when inseminating frozen semen to consider extender constituents and to make appropriate dilutions with thaw media to reduce glycerol concentrations in the extender to safe levels. However, a difficulty with using frozen semen in dogs is that many extender recipes are proprietary and constituents are unknown. Poor handling of frozen semen straws (through relabelling and holding straws out of liquid nitrogen for > 15 - 20 seconds) detrimentally ...