[js1138]

Most purebred dogs let loose in the wild would simply die.

It really depends on what you mean by wild. Feral dogs live on garbage and handouts. Not exactly the wild.

Ibizan hounds might make it. They are fast, strong, and can catch rabbits. Some other large and strong breeds might survive.

[CarolinaGuitarman]

Agreed. Some breeds are closer to the *wild type* than others. My brother has an Alaskan malamute. It is a lot closer to its wolf ancestors than a chihuahua. The former would much more easily be reintroduced than the later. I am also assuming little if any interbreeding with other dog breeds; I am thinking of a genetically isolated population of malamute or chihuahua. The only way some of the old, lost alleles would be reintroduced would be through mutation.