Despite their radical difference in size, these two dogs have something in common - Gibson the Great Dane and Boo Boo the toy Chihuahua are both world record holders.

Measuring a whopping 107cm, gentle giant Gibson was named tallest dog back in 2004. Joining him in the hall of fame for 2007 is tiny Boo Boo who only measures 10.16cm tall and is smaller than Gibson's head.

Gibson looks down at tiny Boo Boo

The two celebrity hounds, who were both bred in America, met up to celebrate Guinness World Records Day 2007.