The Miniature Labradoodle is not a pure bred dog. It is usually a cross between the Labrador Retriever and the Poodle; a Toy, Miniature or a small Standard Poodle. However there are two different ways breeders are breeding the Mini Labradoodle.
1. Some Miniature Labradoodles are being bred as a first cross between a Labrador Retriever and a Miniature Poodle. Some have Toy Labradoodles. These two smaller sizes of Labradoodles are achieved sometimes by surgical insemination or artificial insemination, but not all breeders perform this method of breeding. The resulting puppies may or may not be miniature in size. The theory is that they will be somewhere in-between the miniature poodle's size and the Labrador Retriever's size.
2. Some breeders are producing a much smaller Labradoodle by adding in a third breed. By first downsizing the adult breeding female Labrador Retriever. Some breeders have crossed a Labrador Retriever with a Cocker Spaniel to produce a smaller dog. They are then taking the Labrador / Cocker female and mating it with a Miniature Poodle, either by natural breeding or surgical / artificial insemination. The puppies are ? poodle, ? Labrador Retriever, ? cocker.
The best way to determine the temperament of a mixed breed is to look up all breeds in the cross and know you can get any combination of any of the characteristics found in either breed. Ask the breeder you contact which method of breeding they used to produce the Mini Labradoodle. Not all of these designer hybrid dogs being bred are 50% purebred to 50% purebred. It is very common for breeders to breed multi-generation crosses.