I don't have one but my mum has something called a Catit... it's for cat's but it holds plently enough water for Ellie the yorkie, Emma the Border Collie and Bonnie the crossbred. The love it, it flows constantly over a dome and there is also a reserve.
It's just like this one except without the food bowl on it.
Amazon.com: Catit Waterfall Cats & Puppies: Home...
They all love it