EN
Out of numerous reproductive biotechniques applied in domestic animals, as far as dogs are concerned, it was only possible to obtain in vitro embryos, and to clone a dog, though the results are still unsatisfactory. Until now, transferring in vitro embryos to bitches has produced no offspring. Paradoxically, it has been possible to obtain puppies by cloning. In contrast to farm animals and primates, the problem with obtaining in vitro dog embryos results from the enormous role of the bitch’s oviduct especially during oocyte maturation as well as fertilisation and early embryo development. For this reason, it is very difficult to optimise in vitro conditions, and the adoption of in vitro procedures used in others species is ineffective. Therefore, it is necessary to undertake detailed studies of the dog’s procreation physiology and the functions of different elements of the environment of maturing oocytes, and developing embryos, as well as the factors affecting these processes.