Dog Rocks – Do They Prevent Lawn Burn?

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Robert Pavlis

I first heard about Dog Rocks in a Facebook Group a couple of weeks ago. Someone was looking for a solution to the urine burn marks their dog left on the lawn and Dog Rocks were suggested. At first I visualized rocks that were used to cover up the burn marks, but that is not how this product works. Instead you put the rocks in the drinking water and they absorb nitrates from the water. As one advertisement put it, “less nitrates going in means less nitrates coming out the other end,” With lower nitrates, the grass is not burned and your dog no longer creates spots on the lawn.

Normally, when I review products for the garden I try to be politically correct and bite my tongue, but not this time. This is the dumbest product I have ever come across. A small bit of logic will tell you that it has zero chance of working and I’ll explain why shortly.

Dog Rocks - Do They Prevent Lawn Burn?
Dog Rocks – Do They Prevent Lawn Burn?

Why Does Dog Urine Burn the Lawn?

The first cause that comes to mind is pH. What is the pH of dog urine? The normal pH for dog urine is around 6 to 6.5, which is the ideal pH for growing most plants. So clearly it is not pH.

The next suspect is nitrogen. We all know that if we spread too much fertilizer on lawn grass, it burns. The culprit in this fertilizer is nitrogen. Too much nitrate or ammonium will kill plants.

Compost Science for Gardeners by Robert Pavlis

Urine contains fairly high levels of urea, which is quickly converted to ammonium when exposed to water and then to nitrate through the action of bacteria.

Dogs burn lawns because of high levels of urea.

How Do Dog Rocks Work?

The promoters of this product explain it this way, “Dog Rocks are a paramagnetic igneous rock which create a magnetic field within the water causing a change in the ion exchange. This in turn diminishes the nitrates that are found in the water.” They claim that the rocks absorb nitrate from the water, which results in less nitrate being urinated on the lawn.

As soon as you see “paramagnetic” anything, it’s a red flag for false advertising. I can’t think of a consumer product where paramagnetism provides any benefit.

No scientific studies are available from the manufacturer to prove any of this, which is surprising since “The product was researched for 4 years and then went on the market.” It would only take a few days to put some rocks in water and measure the decrease in nitrates. This would not prove they work but at least it would prove their theory is plausible.

Interestingly, they do post a report from McGill, Office of Science and Society, which discusses why dog urine has high levels of nitrogen, but this report does not mention Dog Rocks, nor does it put any of the blame for high nitrogen in urine on the water that dogs drink.

Video on Dog Rocks

YouTube video

Is Nitrate in Drinking Water a Problem?

Most people use home tap water to water their lawn. This is the same water that is used to fill the dog’s water dish.

Dog Rocks Hotel, Australia, near source of the rock, photo by Mattinbgn
Dog Rocks Hotel, Australia, near the source of the rock, photo by Mattinbgn

Why is it that when you water your lawn with this water you get no grass burn, but when a dog pees on the lawn after drinking the same water, you get a burn? Clearly, the nitrates in drinking water are not burning the lawn!

It is quite obvious to me, that the high levels of urea are not from the drinking water, but from the rest of the dogs diet and the report by McGill confirms this. A high meat diet contains a lot of protein, which contains high levels of nitrogen. This results in higher urea levels in the urine.

Nitrogen levels in drinking water are not the problem. So even if the Dog Rocks did as claimed, they would not reduce damage to the lawn.

Do Dog Rocks Remove Nitrate From Drinking Water?

There is no science to support this idea, and the company promoting the product has no data to support there claim. The scientific mumbo jumbo they use to explain their product makes no sense.

It is unlikely that these rocks reduce the level of nitrate in water but if they do, it would be insignificant.

Solving Lawn Spots

There are four things you can do to stop damage to your lawn from dog urine.

  1. Reduce the meat in the diet. This reduces urea in the urine.
  2. Water the lawn right away after a dog pees. This dilutes the nitrogen level and washes it lower into the soil, making your grass grow better.
  3. Train the dog to pee in the same spot all of the time.
  4. Get a cat!
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Robert Pavlis

I have been gardening my whole life and have a science background. Besides writing and speaking about gardening, I own and operate a 6 acre private garden called Aspen Grove Gardens which now has over 3,000 perennials, grasses, shrubs and trees. Yes--I am a plantaholic!

56 thoughts on “Dog Rocks – Do They Prevent Lawn Burn?”

  1. The nature of the scientific method creates limits in what can be tested. Stating that it hasn’t yet been proven using the scientific method is proof somehow that it doesn’t work is like saying that not being able to imagine something is proof it isn’t real (eg. Platypus was initially considered a fake is people couldn’t imagine it was a real animal). You not being able to identify the mechanism is not evidence that there is no mechanism. It just means we don’t know – but anecdotal evidence suggests something is happening with dog rocks and lawn burn. It pays to keep an open mind if you’re genuinely into science

    • That is sort of true. However, we should not assume that everything that has not been proven, is true, just because it has not been proven.
      In this case we do have a lot of science about the chemistry of urine and rocks, and we understand quite a bit about dog biology. Our knowledge there suggests these rocks do not work.

      More importantly, this is a commercial product. It is the manufacturers responsibility to provide some proof for their claims. That has not happened which suggests they don’t have evidence their product works.

      Anecdotal evidence is useless, unless its testing followed some basic scientific method principals. We have not seen any of those either.

  2. I have two cockers and a ruined lawn and all I know is that whoever finds a solution will make an awful lot of money.

  3. The rocks absolutely work!!!! My shih tzu was burning my lawn. The rocks stopped that. Now with that being said. My dog also acquired an enormous amount of kidney stones. The one was so large it needed to be removed surgically. Bladder stones are caused by minerals. What if any minerals are in dog rocks?

      • I imagine, like the other people that have commented on this post, that they’ve used them and found that the brown patches stop appearing. Those of us that don’t change them frequently enough see the patches start to appear again, showing it’s not just “any rock” that will do. My dogs don’t see the rocks, as I have them in a jug and top the bowl up from the jug when required.

        Your post is now out of date, as they’ve removed the paramagnetic mumbo jumbo from the packaging. But take a look at the reviews on Amazon. Few people say they don’t work – most of the negative comments that are there discus the size of the rocks rather than their efficacy.

        I’ve no connection with dog rocks, other than being a satisfied customer.

        • Reviews on Amazon don’t mean very much. Until someone can explain how they work, or show some real evidence that they work – science says they don’t work.

  4. As someone who worked in a garden centre for many years and had to suggest dog rocks to many customers in that time. Not once did a customer come back for a “refund” on dog rocks because they didn’t work, and believe me that happened with almost every other item- including plants that they failed to water in hot weather….

    It actually isn’t anything to do with the “water composition” as you put it, but the ingestion of water with added substance that helps to de-acidify the urine. Same reason that cats with issues related to dietary intake have to be given supplements to break down structure crystals and prevent bladder/ uti problems.

    But someone who is not actually basing their views on science and repetition in real life testing or who is simply out to judge a product they just don’t understand at all would love to write a review like this.

    I suggest that as a reviewer who claims to know things would actually put their money where their mouth is and actually trial the product without starting to strip back a dog’s diet for no good reason and without the veterinarian qualifications to make such suggestions which can be significantly more harmful to a dog’s health than some “rocks” in their water bowls….

    • What proof do you have that the rocks “add substance that helps to de-acidify the urine”? You have provided no evidence except that you believe they work.

      If something did add a substance to water then it would in fact be a change in “water composition” – you contradict yourself.

  5. I am going to give them a try as I’m at my wits end with the brown patches on my new lawn from dog wee. To those who wish to insult my intelligence and poke fun, go ahead if that’s what makes you feel good about yourself that’s your business. I wonder why they are still on the market if they don’t work they’ve been around a while. I came here to see what people who had actually tried them were saying but instead found a lot negative comments from people who hadn’t, and a number of positive comments from people who had, with a bombardment of insults aimed at the people who say they work. Fingers 🤞 they work for me.


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