7. Carolina Dog
The Caroline dog is also called the “American Dingo”, a rare breed that has genetically been linked with a number of early dog breeds like the Singing Dog of New Guinea and Australian Dingo. They were discovered around 1970 in the Southeastern U.S. living among the cypress swamps. They are versatile and loved by many owners and observers. Compared to other dogs with an estrus cycle two times per year, these pooches have a solitary estrus cycle sometime once a year just like other dogs that are considered wild. These dogs are kept as pets and are also in captive collections.