How Long to Keep Dog Off Grass After Pesticide?

how long to keep dog off grass after pesticide

We all love a perfect, weed-free lawn, right? But at what cost to your dog’s health.

Pesticide poisoning in dogs is extremely common, leading to a whole range of health issues which I will explain further down including the dangers.

But let’s get straight to the point about how long before a dog can go on fertilized grass without getting ill. Here’s the short answer, followed by detail on the dangers and what signs to look out for.

How long to keep dog off grass after pesticide? Most manufacturers state you should wait as long as 48 hours before letting a dog go on grass after spraying pesticide. Alternatively, as long as the grass is dry from pesticide, it should be safe for dogs.

How long after spraying pesticides is it safe for pets? The majority of pesticide manufacturers I looked at, stated 48 hours as being how long after spraying that they consider it safe for pets to go outdoors again where the treatment occurred.

How long after spraying Roundup can I let my dog out?

As one of the leading manufacturers, many dog owners will use Roundup as a pesticide. From what I’ve researched online, the common advice is to make sure the Roundup is dry before letting your dog out.

Some Roundup products can dry in as little as 30 minutes to 2 hours. But of course, if it’s raining or the grass is wet, it can take longer.

To be completely safe, I would still use the 48 hours wait time before your dog can go on fertilized grass.

If your dog is likely to eat grass, then consider safer, natural alternatives to strong chemical herbicides.

how long before a dog can go on fertilized grass
You might want to wait a bit longer before letting your dog out after spraying Roundup.

In the grand scheme of things, pesticides are relatively moderate toxins to dogs. They aren’t as lethal as chocolate for example.

Regardless, they can cause your dog a lot of stress if they come into contact with them.

After you have sprayed a fresh layer of pesticide on your lawn, it is important to keep your dog off the grass until the treatment has fully dried.

The drying time depends on the climate. If you have sprayed the chemical on a humid or drizzly week, it can take many days to fully dry.

On dry, arid weeks, the pesticide product can dry quite quickly. Make sure that the product is completely dry before letting your dog back on the grass to play.

How dangerous is pesticide on grass to dogs?

The most common chemicals found in commercial pesticides and herbicides are called organophosphates. There are other harmful compounds in mainstream weed-killing or insect-killing products, but organophosphates are the big culprits.

These powerful chemicals are also commonly found in flea and tick medication.

So, what is the big deal?

The problem is the dosage.

Flea and tick treatments contain the tiniest of amounts of organophosphates. Therefore, they don’t have a huge effect on your dog.

You are also likely to administer the treatment directly onto the back of your dog’s neck so that they can’t lick it off. Ingesting the product would only lead to mild poisoning.

Lawn and garden pesticides are much more concentrated solutions. The overexposure to the dangerous chemical could be toxic or even lethal to your dog.

The worst part of all is that pesticide poisoning is not just acquired through eating the grass. Your furry friend can also absorb these nasty toxins through their skin and lungs.

That’s a good enough reason to keep dog off grass after pesticide.

Maybe your dog loves to roll around in the grass like mine does? They enjoy that familiar, soft back scratch, and the smells of the garden surrounding them. If the product is not yet fully dry and absorbed into the soil, your dog can rub the solution all over themselves.

This leads to them potentially spreading the pesticide to other areas of your garden, killing other plants that were not intended to be harmed.

Most damagingly, your dog can soak in the product through their skin and fall prey to its toxicity.

As the chemicals can enter the bloodstream via the lungs, here the culprits are the fumes given off by the product.

These are totally invisible to the naked eye, but the pesticide can be inhaled by your dog. This creates a fast track for the organophosphates to start attacking your dog’s nervous system.

“Dogs exposed to toxic chemicals may not exhibit all of the signs of poisoning. In fact, sometimes insecticides will cause the opposite of these symptoms instead, but there will usually be some indication that the dog is not well.” (view source)

Symptoms of pesticide poisoning in dogs

If you did not wait long enough before your dog went on the fertilized grass, they could get ill. But straight after your dog has been exposed to dangerous chemicals, they may not show signs of poisoning straight away.

They may also only show slight signs of poisoning, so you need to be vigilant about your dog’s behavior. The most common symptoms to watch out for are:


A body temperature of over 103F would be considered a high fever in dogs. You can usually tell but feeling the inside skin of their ear, in case you don’t have a thermometer to hand. If it is extremely warm to the touch, your dog may have a fever.

Difficulty breathing

You can notice this if your dog panting excessively and gasping for air.


This is likely one of the most obvious symptoms of poisoning in dogs. Your dog’s body is rejecting the toxins and trying to flush it out of their system.

Vomiting is generally a good thing to try and rid of as much of the toxic substance as possible before it causes further damage.


Much like vomiting, this is a reaction of the body to efficiently get rid of the toxins from the gastrointestinal system. It is highly unpleasant and can cause further dehydration and stress.


This means excessive drooling.

If your dog doesn’t typically drool, this is much easier to notice. For habitually drooling dogs, watch out for significant increases in the amount of saliva they are producing.

Seizures, shaking, and muscle weakness

Since organophosphates attack the connections between nerve endings in muscles, they can cause muscle fibers to twitch and spasm. These spasms can cause full-blown seizures which are frightening to see.

In less extreme cases, they can cause a general lethargy and weakness in the muscles, as your dog struggles to move as freely as they did. Depending on the temperament and overall energy level of your dog, this can be a hard one to spot.

My dog is an old, chunky girl who often spends a lot of time lazing around. Her backflip days are very much over. But do pay attention to changes in your dogs’ movements or involuntary shaking.

Loss of appetite

Loss of appetite can happen over days or even weeks after being poisoned so it is important to keep a watchful eye on your dog’s food habits. Generally, if your dog has not eaten anything at all in 18-24 hours, you need to take them to the vet.


How do you know if your dog is depressed? Somewhat in the same ways you would suspect that a human is depressed. They eat very little if anything at all. They have no interest in toys or playing.

They sleep often and overall carry this heavy energy around with them. You can tell that something is wrong, but you can’t quite pinpoint what. These are all signs that they are suffering from a depressive episode.

Sometimes your dog will exhibit all of these symptoms or a unique combination of them. Poisoned dogs are rarely symptomless because of the nature of pesticides.

Their chemical makeup is too complex and overpowering to swim past your dog’s immune response.

If your dog is exhibiting these terrifying signals of pesticide poisoning, what do you do?

What to do if your dog has come into contact with pesticides like Roundup?

The first port of call is to call the veterinarian.

Even if your veterinarian is unavailable, there should be an emergency vet to contact. Time is of the essence here. The sooner your dog is seen by a medical professional, the better their chances of making a full recovery.

Waiting too long to take action can lead to long-term nerve damage, chronic appetite loss, or even death.

Your vet will first examine your dog and ask you questions about when you think the poison may have been ingested or absorbed some other way.

They will then set about ridding the toxins from your dog’s system. If the pesticide was eaten by your dog relatively recently, your vet may induce vomiting to manually rid the chemicals from the stomach lining.

Another treatment could be the use of activated charcoal which draws out toxins and impurities from the stomach very effectively.

If your dog is suffering from seizures and convulsions, your vet will have medication to calm their body.

Oxygen may be given to dogs struggling to breathe. Plenty of water would be given to a dog that has been vomiting excessively, hyper salivating, and/or suffering from diarrhea.

Overall, if you act quickly, the prognosis is quite positive, with dogs very often making full recoveries post poisoning.


When it comes to pesticide on your fertilized grass, it’s better to be safe than sorry. Please keep your dog off the grass after Roundup or similar for 48 hours if you can.

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Marc Aaron

I write about the things we've learned about owning dogs, the adventures we have, and any advice and tips we've picked up along the way.

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