IS YOUR DOG PEE A PAIN IN YOUR GRASS?

Dr Richard Allport
BVetMed VetMFHom MRCVS
Natural Medicine Centre

Three myths and a truth
 
Summer well and truly was a scorcher! The grass is suffering from a severe lack of rain but also from the dog! Where your dog pees, brown patches develop, which is often called lawn burn or lawn scald. Why does this happen, and what can you do about it?
 
There are several myths about this:
 
Myth one: Only bitches cause lawn burn because their urine is different to that of male dogs. Completely untrue. The only reason why it often seems that bitches cause brown spots but males don't is that female dogs squat to pee, so there is a large amount of pee on a small area of lawn. Males tend to spread their pee over a wide area (applies to humans too, apparently!) so there is less volume of urine on any particular patch of lawn.
 
Myth two: It happens because a dog's urine is too acidic. Nope, not true either. The brown spots aren't acid burns. Grass likes an acidic pH to grow in – anything between 5.5 and 7. The pH of an average dog's urine is between 5.5 and 7. So no problem there.
 
Myth three: It happens because a dog's urine is too alkaline. Now it is true that if a dog's urine were very alkaline it could harm grass growth, but it a rare finding, and not a common cause of brown lawn burn.
 
There are substances that you can add to a dog's drinking water that are alleged to stop brown patches on the lawn. One recommendation is the use Gypsum salts: not only do these not work, but Gypsum (Calcium sulphate) can cause eye, skin, oral, and respiratory irritation in dogs.
 
One particular home remedy, tomato juice or tomato ketchup, likely has its primary benefit through both increased salt and water intake. While salt will make the dog drink more and dilute the urine, increased salt intake can cause problems for dogs with existing kidney or heart conditions. Pure tomato flakes help neutralise nitrogen, but tomato juice and ketchup won't help.
 
Cider vinegar has been promoted as another 'cure' for lawn scald. This may alter the urine pH  slightly, but urine pH is not the cause of lawn burns.
 
THE TRUTH
 
Lawn burns are caused by the high nitrogen content in dog urine. Dog pee has a high nitrogen content because dogs are carnivorous, eat lots of protein, and the breakdown products of protein digestion passed out in the urine are high in nitrogen. When passed on a small area of lawn it acts like a  massive overdose of fertiliser and 'burns' the grass.

The effect will be more noticeable if the urine is strongly concentrated, or if the urine is very alkaline, but it is the nitrogen content only that actually causes the effect.
 
THE CURE
 
First, encourage your dog to drink plenty of water. This will ensure the urine produced is not too concentrated. Secondly, find a product that will bind with and neutralise the nitrogen in the urine
 
There is one product that will do both – WOOF&BREW's Ha-Pee Lawns Herbal Tonic. Most dogs love to drink the tonic so  they will be naturally well hydrated, and the herbs in the blend do really bind and neutralise the nitrogen and help stop lawn burns, as well as promoting a healthy urinary tract in general.
 
And here's an extra grass growing tip: If you're a lazy gardener who doesn't like getting the lawnmower out, sprinkle your lawn with whisky – it'll come up half cut!