Breaking up the dirt and creating a territorial spot is exposing other animals to the pheromones in the dog's feet. Even if your dog doesn't tear up the grass behind them after going to the bathroom, they may wipe their paws around the area in order to leave that same scent.
The main reason why dogs kick grass and scuff the ground around where they went to the bathroom is to further mark their territory. Dogs have scent glands on their paws, and the act of scratching transfers their scent to the ground. There's also the added bonus of making a visible mark.
Dogs like to kick up grass after a poop or pee as an instinctive action. Experts believe it's the dog's way of letting other dogs know that this is their territory, as by kicking up grass and urine, their scent is being spread further.
The kicking motion is a visual display for other dogs and may help spread the scent of urine. Since urine odors are short-lasting, the slashes on the ground serve as longer-lasting marks to indicate the dog's presence in the area.
Siracusa added that these glands in the feet also produce pheromones, meaning that dogs may be leaving these smelly substances in the soil and then widely dispersing them through their vigorous kicking. This could provide a powerful chemical signal to other dogs that they've been there, Siracusa said.
The act of burying waste isn't done because a dog is trying to hide something, though, but rather to spread the scent of their poop further. Kicking up dirt and covering it brings more attention to the feces so it is another way a dog marks its territory after pooping.
Your Dog is Scent Marking There are scent glands on and in between your dog's paw pads. Scratching the grass after urinating or defecating helps spread the pheromones secreted by these glands around the area. Scent marking isn't only about marking territory and isn't limited to just male dogs either.
Our dogs consider pooping as a way of sending a message to other dogs that the ground they just did the deed on, is theirs. By kicking up dirt afterward, they're compounding the scent of the bathroom along with the pheromones coming from their feet glands to create one strong scent.
This is because puppies develop what's called "substrate preference" which means they develop a preference for going potty on certain surfaces. This becomes a problem with puppies trained to go potty indoors on paper and then required to go potty in the yard on grass, dirt or gravel.
Why does dog urine kill grass? The simple answer is nitrates. If you fertilize your lawn, it already has elevated levels of nitrates, so adding even a little more can kill your grass. Dog urine contains a variety of nitrogen compounds that kill grass.
The behavior is also triggered by a precise set of circumstances: Typically, dogs put on this enthusiastic performance just after they urinate or defecate, when they enter a new area with unfamiliar smells or after they smell another dog's poop, Bescoby told Live Science.
How to stop a dog kicking grass up
Dog urine contains a variety of nitrogen compounds. Too much nitrogen will burn the grass and create yellow patches. But appropriate concentrations of nitrogen can actually be beneficial to the lawn, which is why you'll often see rings of thick dark green grass around the yellow patches.