why do dogs eat grass then vomit? a couple of dogs staring at a patch of tall grass with one of them sticking its tongue out

Why Do Dogs Eat Grass Then Vomit? – Find Out Why


Why do dogs eat grass then vomit? You may have thought only cows and goats ate grass. While dogs don’t have the same digestive system as they do, they do tend to eat grass for various reasons. 

A dog may instinctively eat grass when they feel unwell to induce vomiting to clear out the discomfort they may be experiencing. This is nature’s way of purging toxins from the body. 

It’s been observed, however, that dogs may eat a type of grass with long blades which triggers a reflex that makes them vomit.

It is important to note that not too many dogs vomit as a result of eating grass according to a study in 2008.  Out of 1,571 dogs, only 9% appeared ill prior to eating grass and only 22% vomited which dispels the popular belief that vomiting by eating grass is the main reason dogs do it. 

The results were regardless of gender, breed or diet which led researchers to conclude that munching on grass is normal dog behavior.

Is It Safe For Dogs To Eat Grass?

While it is generally safe for dogs to eat grass, there are a few (but extremely important) things to look out for:

why do dogs eat grass then vomit? - a sign on the grass that says caution - pesticide was applied
Photo Credit: grggrssmr via Wunderstock (license)
things that are poisonous to dogs - an image of foxtails that can be harmful to dogs
An image of Foxtails. These can be harmful to dogs
things that are poisonous to dogs - an image of grass seeds that are harmful to dogs
  1. Keep an eye out for a sign that says pesticide or other chemicals have been applied on the ground. If you see such a sign, it’s better to choose a different route to walk your dog for the time being. 
  2. Snails and slugs – May contain parasites called Lungworm which may travel through a dog’s lungs and cause bronchitis or pneumonia and gradually damage the airways. Symptoms to watch out for are coughing, wheezing, and weight loss. 
  3.  Ticks – Dogs can catch ticks when walking on tall grass and bushes. Ticks can cause severe itching and rashes. In severe cases, it can be fatal. Tick diseases can be transmitted to humans so NEVER remove a tick with bare hands. Tick removers can be bought from pet stores or online. 
  4.  Grass Seeds – These can be inhaled, swallowed or penetrate the skin. Even at 1-2 cm, these tiny things can do a lot of damage. Grass seed’s pointy ends can easily enter your dog’s skin and once it’s inside, it may burrow deeper and may cause serious internal damage. They may also carry bacteria which can cause an infection. Injury from grass seeds may result in loss of hearing, loss of eyesight, lung infection, tissue damage, joint damage, and more. Another thing to keep an eye out for is Foxtails which may grow up to 3 inches long.

Depending on where the grass seed(s) burrows, these are symptoms to watch out for:

  • Head shaking
  • Limping
  • Chewing/licking on an area of skin
  • Ear scratching
  • Gagging
  • Difficulty eating
  • Blood in urine
  • Redness/swelling
  • Bloody discharge from the nostril
  • Red eye
  • Swollen area between toes
  • Rubbing the eye/Excessive tears
  • Sluggishness/Laziness

After taking walks, inspect your dog’s skin especially the paws, armpits, ears, and groin. 

In many cases, surgery and a round of antibiotics are required. Please do not take this lightly. If you have even the slightest suspicion that your dog has contracted grass seeds, call your veterinarian right away. 

The adage “an ounce of prevention is worth a pound of cure” totally applies here. 

In warm and dry weather, do not allow your dog to romp in tall grass. While mowing your lawn may lower the risk, keep in mind that Grass seeds and Foxtails can be spread by the wind. Be sure to inspect your pet after walks. 

Should I Stop My Dog From Eating Grass?

According to Dr. Becker, dogs eat grass because they may be seeking nutrients that are lacking in their diet. After all, grass contains Chlorophyll, Magnesium, Potassium, fiber, enzymes and is also a prebiotic which helps balance the microbiome.  

Dogs do this even with the abundance of kibble.
It may surprise you to know that kibble may contain up to 50% carbohydrates.

With this in mind, it may be better to let nature do its thing. 

Other Reasons Why Dogs Eat Grass

  • Pica – A condition where dogs eat non-food items like socks, towels, tennis balls, etc… According to Petmd.com, Pica can be caused by a variety of reasons from nutritional issues to hormonal imbalances, parasites or even diabetes and thyroid problems though some breeds such as Labrador retrievers are more prone to it. If nutrition is the issue, it is suggested to take 3-4 smaller meals throughout the day instead of 1 or 2 big meals to allow for better absorption. 
  • Dogs may eat grass to prevent the build-up of parasites.
  • A dog may have high levels of acid in the stomach and may eat grass as a natural antacid. 
  • Dogs may simply like the taste of grass.
In Conclusion
It is normal for dogs to eat grass then vomit. 
If it happens too often then it may be time to evaluate your dog’s diet. Try a different brand of dog food or go raw.

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**All information in this article if for educational purposes only and is not meant to replace your veterinarian’s advice**


12 thoughts on “Why Do Dogs Eat Grass Then Vomit? – Find Out Why”

  1. Hi! I have been asking myself this question for a long time but I hadn’t Googled it. I had even started to chase my dog each time I spotted him eating grass. I I have learnt in your post that eating grass is not necessary bad. We just gotta be careful. I’ll now check carefully the nutrients that are in my dog’s diet.

    Thanks for this post.

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