ID, please - antique? tool? ornament?

It's brass, shaped like a dog, about 3 inches long with two 
sliding/swivelling parts, one of which is his tail, which 
curves forward and goes through a hole in his head. I have 
no idea what it is, and can't even describe it properly. 
Here's a photo: <http://oldmanscanlon.com/temp/what.jpg>
I'd 
really appreciate hearing what this is - thanks for your 
time.

Ray Scanlon