Why do dogs pee on fire hydrants?

To mark their territory. IF another dog peed there and they can smell the urine, they pee there as a way of saying, F*ck you, bitch this is my neighborhood.

Oh yes, dogs pee on hydrants! Male dogs hoist their legs on almost anything they can. Its how they mark that they were there and all of them try to pee as high as they can as the higher the pee the more dominant a dog is seen by other dogs, We always make the joke that we should life our Chihuahua up so he can have the highest pee marking. LOL! : )

In the wild dogs pee on trees to mark their territory. In the city and the ‘burbs, posts and hydrants often are the only thing a dog can find that is similar to a tree.

Dogs have special places where its like a list of whos been there. If a dog pees in a spot, other dogs will go there to. And leave there sent so that they know who all goes there. Like a message board

I have seen it. Maybe its the color they are attracted to. I believe dogs are only color blind from a distance

Dogs can see some colors like Red for example and i think yellow? or maybe thats some other animal but i know for sure dogs can see Red