Collies are such great dogs, especially with how much I love herding dogs.
How long has the Collies breed of dog been around? 
I'm not sure, but I do know that they are usually medium sized dogs with pointed snouts which I love.
What other herding dog breeds are there? 
There's the Australian Cattle Dog, which of course herd cattle.
Is the Australian Cattle Dog a large breed of dog?
Australian Cattle Dog
The Australian Cattle Dog (ACD), or simply Cattle Dog, is a breed of herding dog originally developed in Australia for droving cattle over long distances across rough terrain. This breed is a medium-sized, short-coated dog that occurs in two main colour forms. It has either brown or black hair distributed fairly evenly through a white coat, which gives the appearance of a "red" or "blue" dog.
As with dogs from other working breeds, the Australian Cattle Dog
Collie
Collies form a distinctive type of herding dogs, including many related landraces and standardised breeds. The type originated in Scotland and Northern England. Collies are medium-sized, fairly lightly built dogs, with pointed snouts. Many types have a distinctive white color over the shoulders. Collies are very active and agile, and most types of collies have a very strong herding instinct. Collie breeds have spread through many parts of the world (especially Australia and North America), and have diversified into many varieties, sometimes mixed