There are 2 types of dogs in the monster manual:
Dog and Riding Dog
Read the description for each to get an idea between the differences of each type of dog. For example, the "dog" entry would be anything from a chihuahua (sp?) to a coyote. The stats presented are intended to be a catch-all for "smaller" types of dogs. I believe this is the type of dog referred to by the article. Just compare the stats to those in the monster manual and they should be similar.
"Riding dogs" are larger dogs, such as Siberian Huskies, German Shephards. I do not think that these dogs are what is intended by the article, but they would be interesting to have as a familiar. The stats are almost identical to that of a wolf and are almost better in some ways.