PHDogs typically go to the bathroom in alignment with the north-south axis
We've known for a while that dogs, along with several other animals, can detect Earth's magnetic fields. But it turns out, they also use it to direct their more personal habits. After watching 70 dogs do their business over a two-year period, researchers who published their work in the journal Frontiers in Zoology found that the pups preferred to go "aligned along the North-South axis under calm magnetic field conditions."
According to the study, this was the first time a measurable, predictable behavioral reaction to the magnetic field's fluctuation has been demonstrated in mammals. It also might be why it takes your dog so long to decide where to go.
(s) bestlifeonline