My sister had a brilliant idea when travelling with their dog - he drinks a lot, so she bought a dinner plate size round plastic bowl, with a lid that fits tight.  She then proceeded to cut a circle in the lid, big enough for the dog to get his head in.  They can sit it on the floor of the car, or even the seat, and no water spills.  Meant to get a picture, but forgot.  It holds enough water for quite a good drink for Esky, and all are happy.

I read about this type of bowl years ago. Made one for my two when they were still alive.   Never got a drop spilled, even when I left it up on the bed. 

I used to make the rim about an inch wide.  It really does work.

Cheers,

Sheba.

We met a traveller near Coober Pedy who made this up.  He insisted I take a photo to share with fellow grey nomads. Just a traditional dog bowl, with a fitted piece of rubber or similar glued on to the dog bowl. He told us and showed us that it never spills a drop The water moves in a circular motion when the vehicle is motion, and the bowl does not tip over.

Thanks for that solarpanel4.  Didn't know they were commercially available.

Cheers,

Sheba.