He wasted no time in taking her advice, but he did decide to make the bloodhound even bigger and more of an “all-around” dog – much like the dog he had wanted as a little boy, one that he could ride and who would be a fun companion. Bridwell remembers speaking to the editor on a Friday, and “By Monday, I had done this little book about a girl and her dog,” he says.
via Scholastic Canada: Authors – Norman Bridwell.
Norman Bridwell is the author of the successful children’s book series, Clifford the Big Red Dog. Anyways, this question popped into my mind and I decided to research a bit and this came up in case any of you were ever wondering.
The Answer: Clifford the Big Red Dog is based off a bloodhound
see the similarities? 
[...] I thought this would be a good followup to the previous “stuff I didn’t know” question. [...]