This is one incredibly cute little dog. From your description and the picture, it is unclear whether the dog is a puppy or a full grown dog, but if full grown, this is one small dog.
Based on the shape of the head, the type of coat and the prominent eyes, it appears to me to be a type of Spitz dog.
Most people think of spitz dogs as being larger, Arctic type breeds that love cold weather. While it is true that there many larger Spitz dogs (Chow Chow, Akita), they also come in smaller sizes.
They were originally bred in norther climates and have thick insulating coats. Most Spitz type dogs have smaller, pointed fury ears and feet that also has fur. The tail usually curls up and over the back. This looks like a dwarf Spitz dog to me. Also known as a Pomeranian, these tiny dogs range from 4 to 6 pounds full grown and come in a variety of colors from Orange, to Sable, Gray, Blue, Brown, Black and White as shown in this picture.
There are other small Spitz type dogs including the Volpino, Japanese Spitz, and American Eskimo. While these dogs are generally very small, the Pom is the smallest.
My best guess, not knowing any of the details of this dog other than what I can see on a photograph, I think he is a Pomeranian.