DNA from the tissue is then inserted into a denucleated egg, probably taken from a spayed bitch, and allowed to divide until there is a clutch of embryonic cells, which are then frozen. You then pay 100 or so dollars a year for storage until the biotech breakthrough, always just around the corner, that will allow cloning to take place on an industrial scale. Breakthroughs aside, the immediate success of pet cloning depends on papering over an image problem, not unlike the one facing chocolate manufacturers at the moment. What that ignores is life on the embryo plantations. Literally dozens of largely nameless and unloved bitches will be indentured to a lifetime of medical interventions in order to bring Fido back.
Cloning is a terribly wasteful technique.
More than 277 embryos were implanted before Dolly the sheep emerged. The rest fell at one of the many hurdles, and cloning dogs, because of their physiology, is much harder. The toll on the worker dogs comes firstly from having their ovaries harvested by cutting open the stomach and sucking them out with a glass pipette. Then further operations are necessary to implant the fertilised eggs, which mostly result in miscarriages or still births. The large number of worker dogs are needed because once a de-nucleated egg and the pet's DNA have fused and started dividing, it can't be stored but must be implanted immediately into a receptive female.