Love your sweet pooch but frustrated by brown polka dot patches on your lawn? Wondering about the safety and effectiveness of the multitude of dog supplements marketed to prevent your lawn’s ailments? Why does dog urine kill your grass?
Dog urine is concentrated nitrogenous waste. When it is deposited on grass in a small area it will kill the grass because too much nitrogen is toxic to the grass. Products on the market are designed to either change the urine pH by acidifying the urine, reducing the amount of nitrogen excreted in urine, or diluting your dogs urine. These products do not work reliably or at all. Options to address damaged grass from urine include not only dog-related products but yard-centric ideas as well. This focuses on training your dog to urinate in a designated area of the yard that you can treat specifically for the excess ammonia or by mulching a small area of the yard for this purpose.
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Don’t blame it on your dog, yet… check your lawn first!
Before blaming your lawn’s yellow and brown spots man’s best friend, make sure the damage is truly related to their bathroom habits. While brown dead grass patches can be caused by the concentration of nitrogen waste in your dog’s urine, several other common causes also exist.
How to tell if the dead grass patches are due to your dog’s urine killing your grass:
Test your grass: try pulling on the grass in the center of a brown patch. If the grass feels spongy and pulls out easily, you may have grass grubs. Grass mold can also cause brown spots in your lawn and will pull out easily in clumps.
I’m a veterinarian and not a horticulturalist, but I do know that brown spots in your lawn caused by urine scalding the grass will NOT pull out easily. Unlike grass grubs and mold, Fido’s urine will only affect the blades of grass while keeping the roots intact.
Once you’ve determined it’s dog urine that has damaged your lawn, you should undertand why.
How is dog urine killing your grass?
Dog urine contains breakdown products of protein called nitrogenous waste. Although nitrogen is an essential component of fertilizer, too much of a good thing in this case can be poisonous. If you observe grass damage from urine, you might notice that there are healthy green rings of grass surrounding the dead patches. This is because the more diluted outer ring of nitrogen deposited by your dog causes the grass surrounding it to thrive.
Four common myths about dog urine and your lawn
Myth 1: Controlling urine pH (making your dog’s urine less alkaline) will ensure their urine won’t harm the grass.
The pH of your dog’s urine is not really what is dangerous to grass. It is the nitrogen and minerals that damages grass. Dog urine is generally a pH of between 6 and 8, but ideal urine pH is between 7 to 7.5. Most grass varieties prefer soil pH between 5.8 and 7.2.
Myth 2: Certain types of dogs cause more harm to grass.
There is no breed of dog predisposed to producing more concentrated nitrogen waste. Female dogs, by virtue of how they squat and deposit their urine in one focal spot, tend to cause more direct lawn damage than male dogs that “sprinkle” urine in different spots. It stands to reason that larger dogs, of course, produce more urine that can damage your lawn.
Myth 3: Female dogs that are in heat will excrete more damaging compounds in their urine.
I don’t know where this myth came from, but there is nothing deadlier about urine for a dog in heat.
Myth 4: Food products like tomato juice, apple cider vinegar, or cranberry extract act to improve urine quality and make it less damaging to your grass.
These additives are all designed to lower urine pH. They do not change the nitrogen and mineral content of the urine which is what is toxic to grass.
Myth 5: Dog rocks that act to lower nitrate in your dog’s drinking water will reduce the nitrogenous waste in their urine.
The main sources for nitrogen waste come from ingested protein. A main goal of therapy for chronic kidney disease is to reduce proteins whose breakdown products create blood urea nitrogen. There has never been an emphasis to reduce nitrates in their drinking water.
How do the products on the market work to change your dog’s urine so it won’t kill your grass?
The products that are marketed to “guard grass” from dog urine utilize compounds to:
- Decrease urine alkalinity
- Encourage water consumption in order to dilute urine
- Reduce ammonia (nitrogen) that’s eliminated in waste
Products that reduce urine pH
If you scan active ingredient labels, the products that act to reduce urine pH (acidify the urine) mostly rely on an amino acid called DL methionine.
DL Methionine: This is an amino acid (building block for protein). Veterinarians use this to treat dogs with a tendency to form certain bladder stones and is typically dosed at 100mg/kg twice daily. Large doses can cause gastrointestinal upset (vomiting, lack of appetite, diarrhea).
Cranberry extract or apple cider vinegar: Food products promoted to reduce urine pH.
Products that dilute urine
Salt: Products may also rely on added salt to encourage increased water consumption and therefore more dilute urine. Adding excess salt should be used with caution in dogs with certain health conditions like high blood pressure or heart disease.
Products that reduce ammonia in urine
Yucca Schidigera: Some products utilize an extract from the Yucca plant. This is most often used in food animal feed to reduce ammonia in fecal matter and therefore reduce odor and harmful emissions. The supplement still has limited data about its effects on urinary ammonia levels, but one study in pigs reported a 12-36% reduction in urine ammonia levels in pigs.
If you’ve learned anything from this article, you should know that diluting urine or reducing the amount of ammonia in urine would make the most impact on preserving grass. However, it is uncertain how effective any of the products are at this task. Unforutnately altering urine pH would not be expected to make much difference. Below is a review of the active ingredients in several popular grass saving dog supplements.
Active ingredients in several “grass saving” pet products
Keep Grass Green by Pet Honesty: DL methionine, cranberry, yucca schidigera, apple cider vinegar
Grass Saver Plus by NauturVet: DL methionine, yucca schidigera extract
Stay green bites Zesty paws: DL methionine, yucca shidigera extract, apple cider vinegar, cranberry
McCrups Green Lawn chews: DL methionine, yucca shidigera extract, cranberry
Dog Rocks: igneous rocks that claim to remove nitrates from water your dog drinks via paramagnetic action
If you would rather not give your dog grass saving supplements, or you’ve tried them and they have not worked, your best bet might be to utilize one area of your yard. Here are some recommendations:
Options other than supplements to prevent dog urine from killing your grass:
Train your dog to urinate in a special area of your yard. This area can be mulched or just a portion of your lawn that you have designated for your dog. You can focus on watering this patch well to dilute the ammonia deposited on the grass. If you choose mulch, avoid choosing cocoa bean hull mulch as this contains toxic compounds for dogs.
If re-seeding your lawn try planting rye or fescue grasses over Kentucky blue grass or bermuda grass varieties which are more sensitive.
Try Gypsum pellets (calcium sulfate hydrate). Gypsum does not neutralize urine as some think, but it may improve soil drainage so that urine does not collect near the roots or crowns of the grass.
Training tips to encourage your pup to potty in one area:
1. Create a designated area of your yard for your dog to use as a potty area. A six-foot radius is plenty of space.
2. Take your dog on a non-retractable leash out to use the potty area. Only use one route to go to the area and return to the house each time.
3. After your dog goes to the bathroom in this area, walk the same path back into the house and once there provide lots of praise or a treat for a reward.
4. Make sure to have all family members adhere to the same process to train your dog.