I just wanted to mention that this works for chickens. A re-purposed spill proof water bowl for dogs. It's a bit up off the floor, but so far they don't seem that interested in perching on it, so bedding contamination is less, but I still had to clean it out some this morning. My long term plan is to get a second one so I can bring a clean one from inside and swap it out. That would make an easier maintenance run, I think.
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this is the Amazon link, if allowed: http://www.amazon.com/gp/product/B0013ERRSK?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00
Heininger PortablePET Waterboy. It holds 3/4 gallon of water, and it has a handle for easy transport. I just did a swap out this morning, real easy. It is not a heated thing, it kind of like a souped up jug.