I found this one Yahoo news today
http://news.yahoo.com/s/ap/20091113/ap_on_re_us/us_tall_dog
San Diego Great Dane named world's tallest dog
LOS ANGELES – A dog named Titan lived up to his name Thursday when he earned the title world's tallest dog.
It was one of more than 30 records announced or set on Nov. 12 — the official Guinness World Record Day — but the only animal to be honored.
The 4-year-old white Great Dane from San Diego is blind, deaf, epileptic and undergoes acupuncture and chiropractic adjustments every three weeks, owner Diana Taylor said.
"Titan is magical," she added. "He's low-key, calm and has a wonderful demeanor about him. He gets along with all dogs, even the tiny ones."
The massive canine is often mistaken by young children for a horse or cow.
Titan's official height, as measured by a veterinarian, is a hair over 3 1/2 feet tall from floor to shoulder. You could add eight inches if official measurements included the head, Guinness spokesman Stuart Claxton said.
Titan weighs 190 pounds and doesn't stand on his hind legs because it isn't good for him. If he did, Taylor figures he would stand 80 or 82 inches tall.