Dog Urine Damage on Lawns: Causes, Cures, and Prevention

Urban Legends About Urine Damage 

Colorado State University

Dog urine damage is a common problem for home lawns, and  

one that has generated numerous home remedies and  

commercial products claiming to be cures for the spots. This  

lawn problem is misunderstood when it comes to causes and  

cures. Dog spotting on turfgrass is caused by the deposition  

of a high concentration of nitrogen (N)-containing compounds  

and associated salts on a small area in the lawn. These  

deposits are often concentrated in a relatively small 

portion of the lawn, resulting in turf injury or death. Some  

common “urban legends” surrounding dog urine damage to lawns are: 

• Only female dogs cause spotting in lawns. 

FALSE. Dog spotting in lawns is most often caused by dogs that squat when they urinate, thus depositing a large volume of concentrated urine in a small area. Most “squatters” are female dogs, but some males do this as well, especially in their own yard. Many male dogs tend to “mark” vertical objects in the landscape (trees, posts, etc.), which presents problems for landscape plants. 

• Dog spots are more common with certain breeds of dogs. MOSTLY FALSE. Dog spotting is more likely to occur (or be more obvious) with larger dogs, since they produce larger amounts of urine.  Dog spots can occur with smaller breeds, especially if the dog tends to urinate in a limited area of the lawn.  

• Dog spots occur because urine is alkaline (has a pH above 7.0)  

FALSE. Dog spots occur because a high concentration of N and salts has been deposited in a very small area of the lawn. In some cases, the added N causes dark green spots and rapid grass growth, without injuring the grass. In other cases, the result is a brown spot – often surrounded by a halo of dark green grass. The browning is caused by the concentrated nitrogen deposited in the center, which 

burns the leaf tissue, and may or may not cause tissue death. The lower concentration of salts on the periphery fertilizes the grass – resulting in a darker green ring. 

• Dog spots can be prevented by using food supplements that acidify a dog’s urine. 

FALSE. Dog spots do not occur because a dog’s urine is alkaline. Products advertised to “naturally” reduce urine alkalinity (including the amino acid, dl methionine, also known as methioform) may cause urinary system problems and can affect calcium deposition in growing bones of younger dogs. The addition of baking soda, potassium citrate and other salts are likewise not recommended as curatives for dog spots. A veterinarian should always be contacted before giving a dog a food supplement known to affect urine pH. There are medically sound reasons for altering urine pH, but the prevention of dog spots in lawns is not one of them. There are no dietary supplements that have been scientifically proven to reduce either the incidence or severity of dog spotting in lawns. 

• Dog spots can be “cured” by sprinkling the affected area with baking soda, gypsum, dishwashing detergent, etc. to neutralize the urine. 

FALSE. The only “product” that can neutralize the urine’s negative effects is water. Gypsum and baking soda (sodium bicarbonate) are salts and may compound the problem. Dishwashing detergents, which act as wetting agents or surfactants, may enhance water movement into and through the soil. While this theoretically could promote leaching and dilution of accumulated salts, some dishwashing detergents can burn grass plants.

Dealing with Dog Spots 

What can be done with the dog(s)? 

• Train the dog to use a non-turf area in the landscape, such as an area covered with mulch or gravel, or select a location where dog spotting will not become an aesthetic problem and damage can be tolerated. This is the ONLY sure solution for the problem! 

• Always provide adequate water for your pet; increased water consumption will dilute urine, reducing the potential for turf injury. 

• While the addition of salt, garlic, tomato juice and other “home remedies” to your pet’s food can increase water consumption (thus diluting their urine), your veterinarian should always be consulted before doing so. The increased salt intake can cause problems for older dogs, as well as for those with heart or kidney conditions. 

• Except for the addition of water to a dog’s food, no additive or supplement should be fed to your pet without first consulting with your veterinarian. Certain additives may increase a dog’s water intake, but can have detrimental and unintended consequences for its health. If the affected spots are green and grass growth is stimulated (no browning is apparent): 

1. Increase nitrogen fertilization frequency and/or the amount of fertilizer to help mask the urine induced stimulation of growth and color; dark green spots will be especially visible on lawns that are not receiving adequate nitrogen fertilization. 

2. Maintain adequate irrigation to prevent accumulation of salts in the soil; drought or lack of water can allow salts to accumulate and injure or kill turf. If the affected spots are brown, (the turf may or may not be dead): 

3. Increase irrigation amount and/or frequency to help dilute salts that have accumulated in the soil.  This may help still-living turf recover, and will dilute salts in those areas where the turf has been killed (allowing for more effective re-seeding). 

4. When turf has been killed, the dead sod and some soil (0.5-1 inch of soil) can be removed.  Re-sod the area with new grass. {See “editor’s note” at the end of this article for section 3} 

5. Zoysiagrass and bermudagrass lawns: Patch using sod from a sod farm, or by transplanting sod from an inconspicuous area of the same lawn. Consult your veterinarian before supplementing a pet’s diet with any product or food additive claiming to reduce dog spots in lawns. Similarly, no “spray-on” product for lawns, claiming to prevent or “cure” dog spots, has been scientifically proven to be effective.

Authors: Alison Stoven O’Connor, Ph.D, CSU Extension Horticulture Agent, Larimer County; and Tony Koski, Ph.D., Extension Turf Specialist; Colorado State University Extension.

No endorsement of products mentioned is intended nor is criticism implied of products not mentioned.

Zoysiagrass and bermudagrass lawns: Patch using sod from a sod farm,

Copyright 2010-2018. Colorado State University Extension. All Rights Reserved. CMG GardenNotes may be reproduced, without change or additions, for nonprofit educational use.  Revised October 2014 

Editor’s note to Florida readers: consult your local Extension agent for grass seed recommendations to use in reseeding dead patches of lawn turf. The recommendations in this article pertain to Colorado’s climate.