Successful embryo transfer in the silver fox (Vulpes vulpes).

Surgical embryo transfer in the silver fox was investigated as part of a larger project concerning the conservation of endangered canine species using modern artificial reproduction techniques with the farmed fox as a model. The animals were chosen on the basis of synchrony in natural oestrus. The timing of ovulation and artificial insemination was determined by measuring electrical resistance in the vagina. Twenty-nine embryos were flushed from eight humanely killed donor females and transferred surgically into the uteri of eight recipients. One recipient female gave birth to two male pups 47 days after the transfer of four expanded blastocysts and one embryo at the 16-cell stage derived from a donor female flushed 10 days after artificial insemination.