Why does my dog’s urine stain the grass?

If you’re a dog parent, you’re probably familiar with those burnt-out patches of grass that frequently
appear in the spots where dogs pee on the lawn. Knowing what causes these marks and how to prevent
them from damaging your Piddle Patch real grass dog potty can help to extend its lifespan.

Why does dog pee kill grass?

Your dog’s urine contains a compound called nitrogen which is produced when your dog’s body breaks
down protein from his diet. When your dog squats down to pee on the grass, it’s this nitrogen that
burns it. Whilst it is true that nitrogen can be good for your lawn (it’s the main ingredient in most
fertilisers), in high concentrations it can be damaging. This is why you sometimes see lush green grass
around the edges of the brown patches.

The extent to which your grass is damaged by the nitrogen in your dog’s pee depends on the size of your
dog, gender, and his diet. But their personal habits also make a difference, as some dogs always return
to the exact same spot to go to the toilet, whilst others will make use of the entire area available to
them however big or small that is!


Your dog’s diet can affect the amount of nitrogen in their urine and the amount of damage to your
grass. Nitrogen is a waste product of protein breakdown, and protein is an essential part of your dog’s
diet as it is needed to maintain healthy tissues in the body, as well as being an important source of

A high-protein diet might mean that your dog’s urine contains more nitrogen. Some dogs need a higher
protein diet, such as working dogs, but most only need a low-protein diet to stay healthy.


Female dogs tend to do more damage to the grass than males. The reason for this is simply anatomy!
A male dog will typically cock his leg against a fence or a tree, so less urine hits the lawn. Whereas
female dogs squat down to pee in one place, so a higher concentration of harmful nitrogen hits the
lawn in this spot, causing the burning.

How do I stop my dog’s urine from burning the grass?

Unfortunately, it is impossible to completely avoid your dog’s pee damaging your grass , but there are
several things you can do to help reduce the damage to your real grass dog potty.

Water it down

As soon as your dog pees on the grass, pour water over the area to dilute the urine. This will lessen the
burning effect. You can also add water to your dog’s food, or encourage them to drink lots to dilute their
urine. There should always be plenty of clean, fresh water available to your dog to keep them hydrated.

Dilute it at the source

There are some products available to add to water bowls that aim to reduce the number of nitrates in
your dog’s diet. This reduces the amount of nitrogen in your dog’s urine, and may help protect your

There are also supplements and products on the market that aim to neutralise the pH (acidity) of your
dog’s urine to prevent damage to grass. You should speak to your veterinarian before using these, as
they can cause other problems such as bladder stones and infections.

Extra walks

It can be helpful to take your dog out to the park or for a few extra walks where they can pee in a
public/shared grass area. If your schedule allows, it might mean that they only need to pee on your grass
once or twice a day, keeping it healthier for longer!


A diet lower in protein, or a diet with a neutral pH might help reduce the amount of damage to your real
grass dog toilet. Your veterinarian will be able to advise you on what diet is best for your individual

Look after your grass

Maintaining a healthy Piddle Patch fresh grass dog toilet will mean that repairing damage caused by
your dog will be easier. However small your patch is, giving it access to natural light, keeping it
watered, and preventing the grass from becoming oversaturated will help to keep it healthier for longer.

When to worry

If you notice any changes to your dog’s toilet habits then it’s important to get him
checked by your veterinarian to rule out any other health problems.

Signs to look out for that might indicate your dog has a urinary problem include peeing more frequently
than usual, straining to pee, passing small amounts of urine in lots of places, finding blood in the urine,
or incontinence.

It is always helpful if you can take a urine sample to your vet to help them make a diagnosis. You can do
this by catching some urine. Ideally, this should be the first urine your dog passes in the morning. Use a
clean, dry container to catch the urine, and store it in the fridge until you can get it to the vet. We don’t
recommend using a jam jar – minute traces of glucose remaining even after washing can upset the results of the


It is unfortunately inevitable that your grass will suffer some damage from your dog’s urine. It is a
completely natural process caused by the waste nitrogen in your dog’s pee. Some dogs will tend to do
more damage than others, such as very large dogs, and female dogs. However, there are lots of
techniques you can use to protect your Piddle Patch real grass dog pad, and if you have any concerns
about your dog’s toileting habits then it’s always best to get advice from your veterinarian.

By Dr Holly Anne Hills