I always thought that you could Sprinkler into pet bowls and meant to set that up on my Farm. But those little ideas always fall to the wayside while other bigger game projects loom, like redecorating the Adventurer's Guild or sprucing up the Dwarf's cave with rockpiles and tables containing Dwarf Helms and Dwarf Gadgets with Internet access.
Laziness eh, dedication to important tasks pays off again, auto-pet bowl watering was never gonna work.