peeing

My mare peed all over the cement
I have never seen or had a horse that ever peed while being groomed on cement.
We had her out for an hr and she had been rode in a nice sandy area and then was walked to the grooming area two min later she let loose then almost slipped in it. She then went into her stall and peed again

There is a new mare in the barn but she acts like a stallion makes a huge racket if my horse leaves the barn or comes to the barn.
Could this be because she might be going into heat. Could it be due to the other horse ?

LOL! I think your mare is excited that there's a new friend at the barn, and it sounds like the two of them are going to be good roommates. I wouldn't worry, some mares also pee as a territorial behavior but it's not an act of aggression, just instinct. I hope they are going to be good friends :)

A girl I know has a gelding that only pees on concrete. It splashes up back all over him. Due to this, all his gear smells strongly of pee... she washes his rugs every week but the smell's always there LOL.

I used to have a couple of mares boarded with me who did that. Especially after being worked. So I told the owners to untack quickly and put them in the stall, let them pee and take them back out for grooming. Worked!

Some horses just don't care where they pee ! My mare never used to pee on concrete, but then she saw my sisters mare do it and now she does...grrr !