SOLVED. Junior novel. City kid who writes on things, pet named "Garbage Dog," pub. 1970s or early 80s. [s]

[Peacegal]

I'm looking for a juvenile novel that was most likely published in the 1970s or early 1980s. I read it as a library book in the very early 90s.

It's the adventures of a city kid who has a habit of writing on all surfaces with a piece of chalk, which often gets him in trouble. At one point he writes the school bully's name on a picture of a caveman...the bully vows revenge and is chasing him throughout the book. There is a small stray dog that the kids call "Garbage Dog," who always seems to be carrying something in his mouth. At one point the dog brings the kids a baby turtle. One day they measure Garbage Dog with a ruler and much is made of the fact that his legs are only two inches long.

[inaword]

The 18th Emergency

[Peacegal]

Wow! That was quick! Solved!!!