Why is my dogs urine killing the grass?

September 28th 2023

Brown patches on your lawn where your dog has urinated can be unsightly, although completely normal, however there are a few things you can try to keep your dog and lawn healthy.

What causes lawn burn?

There are LOTS of theories about why it happens, but which one is correct?

1.       Brown patches are caused by urine that is too acidic.

2.       Brown patches are caused by urine that is too alkaline.

3.       Brown patches are caused by high protein diets.

4.       Brown patches are caused by diets using plant-based proteins.

5.       Brown patches are totally normal and caused by nitrogen in the urine.

The normal pH of dog urine is 6 to 7.5. The pH scale runs from 1 to 14, with 1 being very acidic, 7 neutral and 14 being alkaline. Therefore, a dog’s urine is naturally slightly acidic to neutral. Urinary infections can change the pH of the urine and can sometimes lead to the formation of bladder stones or crystals. Diets that are high in animal protein tend to produce an acidic pH urine, whereas animals that eat plant-based matter (herbivores) produce an alkaline based urine. However, there are very few studies looking at the levels of protein, type of protein and urinary pH in dogs and so we don’t know how much about the effect of different diets in dogs yet.

However, we do know that it is not the pH of the urine that causes the grass to die and turn brown; this is caused by nitrogen in their pee.  When the body breaks down protein, one of the by-products is nitrogen and this is excreted in the urine. It is theorised that feeding high protein diets increases the amount of nitrogen in the urine and may lead to more lawn burning, but this is yet to be proven.

How do I stop my dog’s urine burning the grass?

If your dog is healthy with no urinary problems, then the simplest way is to dilute the urine which involves pouring some water over the top of the area where they have urinated.

Alternatively, if you have an area of your garden where you don’t mind your dog urinating you can train them using kind reward-based methods to only pee in certain areas. For male dogs that like to pee against something you can buy ‘pee posts’ to encourage them to go in one place.

Encouraging your dog to drink plenty of water and stay hydrated should also help. If they are drinking enough or on a wet food then their urine may be more dilute than those dogs solely fed a dry diet.

There are anecdotal tales of giving dogs filtered water to drink instead of tap water, but this has yet to be proven. However, this is something that wouldn’t hurt to try.

Should I give supplements?

Supplements that claim to change your dog’s urine pH should be avoided as this could cause urinary problems. Other supplements that have been suggested including a prebiotic or probiotic, but the science behind this is inconclusive – although these may be useful for digestive problems. In this case it is best to stick to the safe and simple methods of washing your grass off, feeding a good quality diet and ensuring your dog stays properly hydrated.