In a town where so many people take pride in their properties, it’s not a surprise that we get a lot of calls during the summer from folks looking for some kind of treatment for their dogs to prevent brown spots on their lawns after they urinate. There are many products out there so I’m glad that people do seek advice. Trial & error with these items can be dangerous.
The first thing to know is that most people (and supplement companies…) misunderstand the cause behind this dead grass. The thought is that the acid in the urine is “burning” the grass. While urine is acidic, it is not strong enough for this damage. Unfortunately, much like on the human side, “supplements” don’t fall into a category that require any regulations or oversight. Therefore, misguided companies will promote products that are supposed to change the acidity of the urine. The problem with this is that they work… often with detrimental effects. Altering urine pH can cause many problems, the most common is the formation of bladder stones that could require expensive and painful surgery. In general, it’s a good idea to follow this rule of thumb: if something is good for grass, it’s bad for dogs.
The actual cause of brown spots is the nitrogen in the urine. If you know lawns, you know that nitrogen is actually a nutrient that plants need for good growth. So how can this cause damage? Just like most good things, too much will usually be bad. So, in the case of brown spots, these areas of grass are essentially over-fertilized. The good news is, there are things you can alter in your lawn care that will have beneficial effects.
Many homeowners will spread lime thinking they will buffer the acid and it will have some beneficial results, but only because it is also slightly lowering the amount of nitrogen available to the grass. One trick that does work is simple dilution of the urine when the dogs hit a certain spot. Have a hose or watering can handy when you take the dog out. When the dog goes, just pour a gallon or so on the area and this will decrease the nitrogen levels and force much of it down into the deeper soil. If you are someone who fertilizes, then the easiest thing is to use a low-nitrogen fertilizer. There are several pre-made products with low nitrogen levels. Most companies do not recommend using no-nitrogen products as this can actually create green spots as the urine starts providing missing nutrients. There are also companies that will make custom fertilizers so you can tweak the nitrogen levels depending on how your particular dog’s urine interacts with your lawn. Otherwise, it is typically recommended to use a fertilizer that is 3% nitrogen. Regardless, with these horticultural options, it’s easier for owners to follow my most common advice: treat the lawn, not the dog.