What animals are breed able with dogs? <Except dogs>
The main criteria of any particular species is its ability to reproduce. This is because the chromosomes of the male and female in question correspond in number. No match, no conception, no reproduction.
Scientists at present, however, are able to introduce genes of one species into another in an asexual manner. Frankenstein is truly at the door, for now pigs have been made with fluorescent noses (from a fish gene) and a goat can secrete a silk-like fibre (from a spider gene) from its mammary glands for commercial purposes.
The question we should be asking is if we really have the right to trump nature in such a way.
Interspecies breeding is very difficult. The two animals need to be genetically compatible, which is rare.
Within one genus interspecies breeding is often possible. Dogs have been successfully interbred with wolves, coyotes, dingos and jackals. There are stories about dog-fox hybrids, although this has not been proven.
Naturally, it isnt possible as time has passed and the animals probably don't have the same amount of chromosomes in order to copulate, and reproduce. But scientifically they can infuse the eggs and sperm of 2 closely related organisms such as a dog and a wolf and form a new breed.