I used these in my stalls: (the smaller ones)

https://www.bigdweb.com/product/heated+water+bucket+10+qt.do?sortby=bestSellers&refType=&from=fn&ecList=7&ecCategory=100667
I drilled a hole in the stall wall, or water bucket door, and ran the cord out right under the bucket so the horse could never reach it.

---------

I used these outdoors. Put a piece of plywood along the fence, drilled a hole behind the tank to run the cord where the horse could never touch it. It's the size of a manure tub and holds 3 times what a bucket does. Easier to clean than a stock tank. When I had more horses, I used 2. and you can carry buckets of water out and dump them in to fill. no hoses in winter.

https://www.jefferspet.com/products/heated-16-gallon-tub

----------

and for cats:

https://www.jefferspet.com/products/premium-heated-pet-bowl

----------

and then I moved to California! LOL. But seriously, after trying everything, these items above were wonderful in Cleveland!