My Dog Licked Roundup! (The Risks, Explained)

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After finishing off the Sunday afternoon gardening by spraying weeds with your trusty Roundup weedkiller, you finally plop down on the sofa for some much-deserved TV time.

However, out of the corner of your eye, you spot your dog licking the grass that you were treating with herbicide just five minutes earlier.

Startled, you realize, “My dog licked Roundup! Is it going to die?”

Well, as dangerous as Roundup might seem, it is unlikely to cause any serious issues other than GI problems such as diarrhea and vomiting.

These effects are often temporary and will last up to a maximum of 48 hours.

In very rare cases, Roundup ingestion can lead to convulsions, pulmonary edema and death.

However, for Roundup to be fatal to a dog, it may need to ingest up to a few liters of the weedkiller before that becomes a possibility.

After your dog has licked Roundup, it may be a good idea to give it milk or water in order to dilute the substance in the stomach. Feeding a plain, bland diet or administering medications such as Pepcid AC or Prilosec can also help to calm upset stomachs.

If your dog does not get better over the next 24 hours after consumption, ingested a lot of Roundup relative to their body weight, or is acting strangely in any way, then it is recommended to contact your vet or a poison control hotline immediately.

What’s In Roundup, Anyway?

The primary active ingredient in Roundup is the isopropylamine salt of glyphosate, which works by blocking the shikimic acid pathway and thereby inhibiting the growth of sprayed plants.

Depending on the version of Roundup, other ingredients are also incorporated in the formulation. These add to the efficacy of the product as they can help to enhance the effects of glyphosate.

For example, polyethoxylated tallow amine (POEA) is included as a surfactant to allow greater herbicide penetration. However, the addition of these additional inert ingredients can add to the overall toxicity of the substance to unintended mammal and aquatic bystanders.

Can Roundup Hurt My Dog?

Can Roundup Hurt My Dog?

In terms of acute toxicity, you will be glad to know that the risk of poisoning for mammals is low, though as mentioned above the addition of surfactants can increase the toxicity.

Therefore, if your dog has licked Roundup in relatively small amounts from treated plants, it is unlikely to pose any significant risk- especially if the Roundup has dried.

In smaller quantities, Roundup can cause gastrointestinal issues such as diarrhea and vomiting. Your dog may also drool, appear drowsy or weak and have a loss of appetite.

These effects are temporary and should pass within 48 hours.

The effects of Roundup ingestion are more potent if the Roundup was wet when ingested, compared to if the Roundup was already dry and absorbed by the plants.

If your dog only has a few licks of Roundup, it should not lead to any significant problems in the long term. However, if your dog suddenly ingests a large amount of Roundup, a few different problems can occur.

The amount of Roundup required to result in adverse effects in dogs is shown in the table below.

A Summary of the Concentrations Required to See the Effects of Roundup in Dogs


No Observed Adverse Effect Level (NOAEL)

Lowest Observed Adverse Effect Level (LOAEL)


300 mg/kg

1000 mg/kg

Polyethoxylated Tallow Amine Surfactant

21 mg/kg

42 mg/kg

Units: Milligrams Per Kilogram of Bodyweight

No Observed Adverse Effect Level (NOAEL) refers to the highest dose of Roundup consumption where there is no observable toxic or adverse effect.

Lowest Observed Adverse Effect Level (LOAEL) refers to the lowest dose of Roundup ingestion which will result in an observable toxic or adverse effect.

The side effects of Roundup consumption are primarily caused by the POEA content.

Some of the short term adverse effects of Roundup consumption may include:

  • Reduced blood pressure
  • Reduced blood circulation
  • Increased blood pressure
  • Hypersalivation

When overdosed, long term adverse effects of Roundup consumption may include:

  • Weight loss
  • Frequent vomiting and diarrhea
  • Lower blood calcium
  • Lower protein concentration

Long term consequences will be observed after continuous feeding of glyphosate over a 3-month period.

High doses of Roundup ingestion can initially cause hyperactivity and a faster heart rate. This is shortly followed by depression, incoordination, and a low heart rate.

In rare cases of Roundup toxicity, consumption of Roundup can lead to pulmonary edema, spasms, and death.

In some cases, dogs may display no symptoms after ingesting Roundup as their body is able to remove the foreign substance through excrement in their stool or urine.

Can Roundup Kill A Dog?

Yes, it is possible for Roundup to kill a dog, but it would need to ingest a large amount relative to their bodyweight. Generally, if your dog only licks Roundup, the amount is unlikely to cause any significant effects outside of temporary stomach issues.

What Should I Do If My Dog Licked Roundup?

What Should I Do If My Dog Licked Roundup?

If your dog licks any Roundup, encourage it to drink as much water as possible as it will help dilute and remove the Roundup from their body.

During the early stages (within 1-2 hours after ingestion), you can also feed your dog milk to dilute the ingested Roundup. Feeding activated charcoal can also help remove Roundup from their body.

If they have licked Roundup, they may show symptoms of digestive issues. To reduce stomach acid and calm their digestive system, Pepcid AC or Prilosec can be administered.

The active ingredient in Pepcid AC is famotidine. The recommended dosage of Pepcid AC for dogs is 0.25-0.5 milligrams per pound of bodyweight every 12 hours.

The active ingredient in Prilosec is omeprazole. The recommended dosage of Prilosec for dogs is 0.25-0.5 milligrams per pound of bodyweight every 24 hours.

After licking Roundup, you may also feed a plain diet with foods such as:

  • Boiled hamburger
  • Fat-free, skinless chicken
  • White rice

Giving your dog easy-to-digest foods such as the ones above will help to keep its digestive system from becoming overburdened as it works to process the glyphosate and POEA.

If your dog has licked a relatively tiny amount of the substance, all you will likely need to do is to simply keep an eye on the pup and take note of any strange behaviors.

You should contact your veterinarian or ASPCA poison control hotline immediately when:

  • Your dog has consumed a large amount of Roundup (relative to the numbers shown in the above section ‘What Happens if My Dog Licks Roundup’)
  • Your dog is not getting better within the next 24 hours
  • Your dog begins to behave strangely such as displaying extreme lethargy or develops seizures

(Note: ASPCA’s contact is 888-426-4435. They are likely to charge a consultation fee- but in most cases this is worth the peace of mind it brings!)

Is Roundup Safe For Dogs After Drying?

Is Roundup Safe For Dogs After Drying?

According to the back label of the product, areas treated by Roundup are safe for humans and pets to play on as soon as the weedkiller has dried.

However, this advice isn’t intended for the safety of your dog, as it instead notes that this will prevent the substance from being tracked to other parts of the lawn.

Skin irritation and dermatitis has been reported when physical contact is made with Roundup, though according to the European Chemicals Agency it is unclear whether it is glyphosate or the other co-formulants that possess the irritant effect.

Since glyphosate targets plant cells and not those of animals, it should in theory only have minor impact when touched- even while it is still wet.

Nevertheless, it would still be best to keep your dog off any treated areas until the Roundup dries, and how long this takes will depend on the amount used and environmental factors. A good general rule is to keep them off a treated lawn for the next 24 hours, at the very least.

In Summary

If your dog licked Roundup that was sprayed on treated plants, it is possible that it will experience GI problems such as diarrhea and vomiting within the next 48 hours.

The effects of Roundup are often temporary, and your dog should begin recovering shortly afterwards.

You can help with recovery by providing milk or water to dilute the ingested Roundup, or feed medications such as Pepcid AC to help to soothe its stomach.

Feeding your pup a plain diet for the next day or two will also help to ensure that its digestive system heals as quickly as possible.

If your dog consumed a large quantity of Roundup, or if they haven’t improved in the last 24 hours, contact your vet or a poison control hotline immediately for the best course of action.

Whilst ingesting Roundup is generally not fatal, there is the possibility that your dog’s body is unable to process the foreign substance (especially in an overdose) and a deadly consequence may result if not promptly treated.

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