why dogs eating grass

 Why Dogs Eat Grass? 


Your dog does some very quirky things – they prefer sitting on you instead of next to you, they never seem to remember that the glass door needs to be open in order to walk through it, and they love to eat weird things.  When those weird things include grass and other plants, you start to wonder if maybe your dog is ill, weird, or needs a therapist.  We did some research on the topic and have the results for you: don’t worry, your dog is (mostly) normal, even if they love some salad now and then.

What Are Some Reasons Behind Grass Eating:

The first step in any investigation is thinking of possible causes for a behavior.  In the case of grass-eating there are three top possibilities: dogs eat grass out of boredom, grass helps their digestion, or dogs are trying to meet a nutritional need not being met by their diet.

If your dog eats grass and you’d prefer they don’t, some basic steps may help them quit the habit.  Try offering a greater variety of toys that offer extra stimulation and novelty to distract them from their own salad buffet.  It might also be a good step to review their diet.  If you use alternative diets such as raw, vegetarian or home-cooked food, speak with your vet to make sure they are getting their full dietary requirements.  Dietary review can also help dogs with their digestion, which could be another cause for eating grass when it’s available.

What the Research Says:

Essentially, there is very little research on this topic as vets mostly view dogs eating grass as a normal behavior.  One researcher, Dr. Benjamin Hart, has performed an extensive survey study of 1,571 dogs and their grass munching behaviors1.  Here is what he found:

  • 68% of dogs eat grass on a daily or weekly basis. If your dog eats grass, take a deep breath because they are (mostly) normal.
  • He also found that of all dogs who eat grass, only 24% vomited afterwards. While it seems like dogs only eat grass to make themselves sick, it is actually unlikely they will throw up at all.
  • Only 8% of dogs who ate grass showed symptoms of illness before dining. This makes it unlikely that dogs are attempting to fix themselves by seeking out a specific ingredient.
  • He also found younger dogs more likely to eat grass than older dogs, and for diets to play no role in whether dogs were likely to eat grass. Included in his study were dogs fed vegetarian diets, raw diets, commercial diets, table scrap only diets and many other varieties.

All of these findings, together, point towards no particular reason for dogs to eat grass.  The best theory right now is that dogs eat grass as a holdover from their wild ancestors.  It is believed that eating grass helps to expel intestinal parasites.  Grass provides roughage which speeds up and ‘cleans out’ the bowels, possibly expelling nematodes in the intestinal tract with them.  This might explain why younger dogs are more likely to eat grass than older dogs; intestinal parasites affect their health and growth more profoundly than it does in adult dogs.  Despite this sound reasoning, this is still a theory and almost impossible to prove without a doubt.

What to Watch For:

While most veterinarians regard grass-eating as mostly normal, your dogs can harm themselves if eating too much or the wrong kind of plants.  While some plants that are poisonous for your pet naturally repel dogs, sometimes their curiosity will get the better of them.  Before planting a new addition to your garden be sure to check out the exhaustive list the ASPCA has available on their website.  Symptoms of a toxic reaction to a plant will mimic other poisonings, with vomiting, diarrhea, drooling, depression, and lack of appetite.

Sometimes dogs might overindulge their grass-obsession and overeat.  In most cases this will result in vomiting up the grass.  In some cases, especially with long-stemmed plants, grass knots up in the stomach and causes a blockage.  If this happens, your dog may not be able to vomit up the blockage and may need veterinarian support.  Luckily, this is not a common occurrence.  Symptoms of a digestive blockage can include lack of appetite, vomiting, painful or bloated abdomen, or depression.  See your veterinarian if either of these situations occur.

If your dog is eating grass, it’s ok.  If your dog is eating grass and then vomiting, it’s still ok.  Eating grass, as the studies show, is typical for most dogs and does not cause real harm.  While our beloved family pets often give us lots of cause to worry, we can lay this concern to bed as an eccentric behavior that is mostly harmless.

By Lauren Pescarus

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