At first I was at a loss to explain why the phrase "dog-eating catfish" ranked among the most popular search terms here over the past week after all, it was two years ago that Kuno, the legendary Dachsund-swallowing catfish of Moenchengladbach, Germany, is believed to have perished during a heat wave in the region. Then I began perusing news stories about the record-breaking, 646-pound giant Mekong catfish caught in northern Thailand last month and discovered that many of the articles mentioned a related species known to ichthyologists as Pangasius sanitwongsei but popularly called mystery solved! the "dog-eating" catfish. Evidently some of the folks who read about it were curious to know if the creature really does eat dogs a question to which, I'm sorry to say, I do not have the answer, though I'm skeptical.
Read more:
Germany's Legendary Dog-Eating Catfish Found Dead - Reuters Massive Catfish Caught in Thailand - Associated Press The Imperiled Giants of the Mekong - American Scientist Online
Giant Catfish Critically Endangered, Group Says - National Geographic
Read more:

Comments
Hey people they caught the catfish.
More info at, http://user.bahnhof.se/~wizard/GUSTeng03/artiklar_moenchengladbach.html
Ok.
Apparently it is called the dog eating cat fish because they use dog meat to catch the fish.