Save Your Grass from the Dogs

Fighting “Female Dog Spot Disease”

You worked hard to make your yard a lush, green carpet. Then you let your dog out to romp — and do her business.

Before long, ugly brown spots of dead grass appeared, marking clearly where your dog urinated.

Why does dog urine burn grass and what can you do about it?

It’s the Nitrogen

A common assumption is that acid in a dog’s urine causes the grass to burn and die. This is not the case.

Dogs (and cats) eat a lot of protein and normal bodily functions break it down. Excess nitrogen is removed by the kidneys and is expelled in urine — and it’s the nitrogen that burns the grass.

Female dogs are more of a problem than male dogs not because their urine contains more nitrogen, but because they usually squat and empty their bladders in one spot. The concentrated blast of urine acts as a massive dose of fertilizer in a single area, which causes the dead grass.

In fact, horticulturists refer to the problem as “female dog spot disease.”

Male dogs lift their leg and use small bursts of urine to mark. It’s a smaller amount of urine on many different areas, including trees, fences, or other higher-up attractions.

Feces also contain nitrogen, but it is more slowly released and is often picked up before it can do any damage.

Tomato Juice?

You may have heard that adding tomato juice to your dog’s diet can alter the acidity in the urine. The only thing adding juice might do is make your dog’s urine more dilute and therefore less concentrated. Dietary changes won’t help because the pH is not the culprit.

Talk to your veterinarian before making any changes in your dog’s diet. Adding salt might make your dog drink more water, thereby diluting her urine, but it’s not safe for dogs with kidney or heart conditions.

Avoid supplements advertised to change your dog’s chemistry in order to eliminate burn spots.

Ask your veterinarian about adding some canned dog food or water to your dog’s kibble to help dilute urine. Also, premium dry dog foods have a higher-quality, more digestible protein, which can lower the nitrogen content of your dog’s urine.

If you do not make any changes to your dog’s diet and you notice your lawn no longer has burn marks, it might signal a bladder problem. Infections make your dog urinate more frequently and in smaller amounts. Check with your veterinarian if you suspect your dog might have an issue.

Grass Matters

The kind of grass you put in your yard also determines how well it will hold up to dog urine. Fescue and perennial ryegrass were most resistant, and diluted amounts of urine actually act as a fertilizer, according to a study done by Dr. A.W. Allard, a Colorado veterinarian.

Kentucky bluegrass and Bermuda grass were the most sensitive.

The study showed that it’s the concentration of the urine, rather than the volume, that does the most damage.

How to Stop Lawn Burn

Most mild burn areas will repair themselves. But the most effective way to combat lawn burn is to water the area immediately after your dog urinates.
Use a fertilizer on your lawn that has reduced nitrogen.
Reseed your lawn using the urine-resistant grasses.
Make sure your dog has access to plenty of fresh water. The more your dog drinks, the more dilute the urine will be.
Another way to keep your grass green is to train your dog to urinate and defecate in a designated area. It is easier to train puppies, but older dogs can also learn to go in a certain spot. Use small (pea) gravel or mulch.

For a male dog, add a marking area — a fake fire hydrant, a large rock, bird bath, etc. Use a short leash and bring your dog to the spot. Use a command such as “Potty” or “Do Your Business.” Reward him with a treat — but not too many, as the protein content will add more nitrogen to the urine. Be consistent. It might take a few weeks to a few months to train for this behavior. Don’t let your dog wander unsupervised in your lawn during this time.