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Why Is My Dog Eating Grass All of a Sudden?

Disclosure: This post may contain affiliate links that pay me a commission. As an Amazon Associate I earn from qualifying purchases. Full disclaimer here.

What are dogs up to when they start eating grass all of a sudden? Don’t they like what we are feeding them? Let’s look at some reasons dogs eat grass so that we can decide if a trip to a veterinarian clinic is warranted.

Apparently, vets get this question all the time.

So you can be sure that you are not alone in your concern about your dog’s dietary needs.

Disclaimer: If there is the slightest hint of a health issue in your dog, please make an appointment with your vet ASAP.

Grass Eating in Dogs

There are many answers to the question why a dog starts to eat grass all of a sudden. Some of the reasons are harmless, others more serious, demanding veterinary intervention.

And just in case your vet starts talking about ‘pica’, here is a definition:

Pica is the consumption of non-food substances.


Now of course, non-food items can cover a wide range of things such as sticks or dog poo or, hopefully not, little toys. But what we are specifically looking at, in this article, is grass.

7 Possible Reasons Why Dogs Eat Grass

The reasons most commonly cited include:

  1. The dog is unwell – consult a vet if at all in doubt.
  2. The dog could be injured or in pain – again consult your vet.
  3. Lack of fibre in their diet
    It is true that fibre comes from plant sources. However, healthy versions of dog food (affiliate link) can be found whereby fibre can been incorporated into the dog’s diet.
  4. Other nutrients missing from the diet
  5. It can be an instinctive habit that heralds back to pre-domestic times.
  6. It could be simply something to do to pass the time.
  7. It might actually taste nice particularly with all the new spring shoots.

The digestive system of domesticated dogs has changed over time such that they are no longer classified strictly as meat-eaters only (carnivores). They can handle many other food groups, hence being labelled omnivores.

Read the label on commercial dog foods. You might not know that ‘cellulose’ is a broad term that can be used for a number of “edible” sources, not all of them food.

Fibre vs Fibre

(Affiliate links included below:)

Fibre is a real aid in digestion and can help alleviate excessive bowel action (diarrhea) or lack of same (constipation).

There are actually 2 types of fibre, each having a very different affect on the intestinal tract.

  • Soluble Fibre – gas producing if too much so therefore should be gradually introduced to the diet
  • Insoluble Fibre – not gas producing but absorbs water as it passes through the system, hence the need for water. Too much of this type of fibre can lead to vomiting and other digestive issues.

We have a friend whose dog is so, so overweight. The habit of giving constant dog treats has been confused with showing affection. The owner obviously means well but the excessive weight is not good for the dog which is now ready for a good weight-control program.

That’s where fibre can come in handy. Fibre in the diet can help the dog to feel full more quickly so he consumes fewer calories overall. Mind you, I don’t think the dog in question ever felt hungry. But a little more fibre added to the diet could well help to reduce those kilos.

High Fibre Dog Food (affiliate link)

Why Do Dogs Eat Grass and Vomit?

It doesn’t always happen, but often you will catch your dog eating grass and then regurgitating it all.

So what is happening when the dog starts vomiting after eating grass?

  • It can mean that they are feeling sick.
  • They might have overdone it with the last meal and need to get rid of some of it.
  • It can still mean that there is something missing from their diet. Perhaps they have overdone the fibre substitution, by eating too much grass in one go. This can then lead to vomiting.
  • Perhaps the grass has been sprayed with something (not good) and the dog needs to get rid of his last mouthful as fast as possible.
  • Some say it can happen when the dog is bored but that is a difficult one to pinpoint. Perhaps this can be confirmed if the habit stops on the days when you have really entertained your dog in some way. There are some great dog entertainment toys (affiliate link) on Amazon.

But as mentioned, vomiting after eating grass is not the norm.

What If My Dog Starts Eating Grass All of a Sudden?

If nothing has changed in your dog’s diet or environment I wouldn’t waste any time and would go straight to a nearby veterinary clinic. Always consult your vet if in doubt.

This is even more important if you have noticed your dog losing weight and/or suffering from diarrhea. And a vet visit is definitely a must if you suspect a fertilizer or weed killer or toxicity in a garden plant.

A trip to the animal clinic will most likely allay any fears. The vet may make a number of tests such as blood, urine or fecal tests. Even a body check can reveal areas of discomfort.

Look for what else might have changed in the dog’s environment and diet:

  • Do you have to work longer hours, leaving the dog to her own devices?
  • Has a new pet been brought into the home and now competes for affection?
  • Are you working from home as a result of recent Covid restrictions and lockdowns? Perhaps the change in routine has troubled your pooch.
  • Have you changed dog food brands?
  • Have you made changes to the dog food that you prepare yourself at home?

Regardless of possible changes that have caused sudden grass eating, make sure there are bowls of water available for drinking. Then monitor your dogs habits and condition over the next few days to make a decision about the need for further veterinary examinations.

Pampering Dogs