Affenpinschers, Chihuahuas, Pekingeses and Papillions are some of the smallest dog breeds in the world. They all are bred to be indoor dogs. More »

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The Russian toy is the smallest breed of dog on average, and ranges in weight from 3 to 6 pounds and 8 to 10 inches in height. Toy fox terriers are a close seconds, with an average weight between 3 1/2 to 9 pounds. More »

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Miniature or teacup Yorkshire Terriers, also known as Yorkies, are available to purchase online through the websites Elvis Yorkshire Terrier, Teacup Puppies Store and Puppy Find. Teacup Yorkshire Terriers are the smalles... More »

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Chihuahuas are the smallest dog breed in the world and one of the oldest breeds in North America. A state in Mexico serves as the breed's namesake. More »

While several dog breeds are regarded as more intelligent than others, the breed that receives the most votes in a survey of more than 120 veterinary professionals is the border collie. Praised as hardworking, energetic ... More »

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The world's biggest breed of dog is the Great Dane. As of 2015, a Great Dane named Zeus, who stands 44 inches high at the shoulders, holds the world record for largest dog. More »

The fastest dog breed in the world is the greyhound. Greyhound dogs can reach speeds up to 45 miles per hour with unsubstantiated reports of exceptional greyhounds reaching more than 50 miles per hour. More »