Though groups like the American Kennel Club make very specific designations about breeds and breed hybrids, there continue to be new breeds and breed variants developed all the time, as well as "up and coming breeds" not officially recognized by kennel clubs and experts. (Many dogs not purchased directly from breeders are also mixed-breeds of some kind, or have less than purebred ancestry.)
If you do not have time to exercise your dog daily with a brisk walk and lots of running choose a breed that does not have high exercise requirements. All of the breeds who require high amounts of exercise make terrific jogging, hiking, and ridding companions. So if you want your dog to accompany you on long runs choose one of these highly active breeds built for endurance and as much exercise as you can throw at them - they will love you for it (and a tired dog is not destructive).
So keep in mind that if you choose a breed with a long coat you will either need to get it clipped regularly if you want to avoid brushing it so much, or if you choose to keep it long or even medium length you will have to brush it every day.
In Great Britain the Kennel Club maintains a list of “vulnerable native breeds.” This refers to breeds that were developed in the UK which register fewer than 300 individual dogs per year. There are currently about 29 breeds on this list, with more breeds on the Watch list, meaning they are close to Vulnerable status. Although the Kennel Club in Britain registers fewer dogs than we do in the U.S., the situation with purebred dogs in the U.S. is similar. While the Labrador Retriever - the top dog registered by the AKC for over 20 years - has tens of thousands of individual registrations every year, other breeds have far fewer numbers. Beyond a few popular breeds, most breeds have relatively small numbers of dogs registered each year. We have many breeds in the United States which register only a few hundred individual dogs per year.
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