A Vet’s Take On Why Dogs Eat Grass

A Vet’s Take On Why Dogs Eat Grass
A Vet’s Take On Why Dogs Eat Grass
Decoding grass chewing


Q: Why does my dog eat grass?

A: Ah... This is the $64,000 question. Grass eating among our canine friends has a number of theories as to origin. I get this question many times a year, and as yet cannot come up with a meaningful single reason. I can say that I've seen grass chewers on occasion get a good nasal cleanse, as the thick blade of grass occasionally gets on the wrong track and scurries out an unsuspecting nasal passage. It's highly unlikely the intent is to cleanse that particular orifice, however!

Dogs do not have the means to digest grass, as they lack the enzymes needed to break down the fibres. Thus, there is little nutritional value in it for them. One reason for eating grass may be due to a feeling of nausea. It is possible that dogs learn this is a temporary solution for stomach irritation.

On occasion, I have seen dogs lick at the air, often showing swallowing behaviour, then rush out to the great outdoors to seek out a thick patch of the green stuff and furiously chomp and chomp until the urge abates. Then promptly throw up. On following these dogs endoscopically, they often have an inflammatory condition in their stomachs or redness around the lower esophagus, which can indicate gastric reflux or inflammatory bowel disease. The situation can be troubling for the owner as the dog is often quite restless before getting out to graze. If your dog looks as if he or she is irritated and extends the neck and begins repeated swallowing motions, it may be time to visit your veterinarian to check out what might be happening. These conditions are treatable with either homeopathic medical intervention or conventional therapies. Diet may also play a role in the condition. A thorough review is in order.

Some dogs can also develop a form of stereotypy behaviour (obsessive-compulsive disorder) and become fixated on grass chewing, but this is relatively rare.

Then there are the select few who search diligently for that particular luscious, thick, juicy blade and then gently savour it. Only the finest blades for me, thank you, and only of particular types. These dogs seem to enjoy their habit and do not suffer any of the previously-reported repercussions, such as vomiting. Grass does not seem to hurt them as long as it doesn't contain herbicides or other toxins.

For those with a scientific bent, an additional theory related to the grasseating behaviour of our four legged companions has to do with their evolutionary past. For ancestral dogs to have survived successfully, they would have needed good hunting abilities in order to feed and nourish their young and survive as a pack. Grass eating may have evolved to help conceal their scent from their prey in the same way that rolling in foul offal is sometimes thought to.

Another common theory is that dogs will eat indigestible matter if they are excessively hungry or if their nutrition is poor, so this must always be a consideration. If you are preparing homemade food, be sure to consult a professional to make sure the nutritional balance is correct.

Dogs are more omnivorous than cats, and many would also like to eat far more than they're fed. In the absence of a midday meal some may simply enjoy the process of eating. One can never rule out that for some, a nice patch of tasty clean crabgrass may simply give the momentary impression of an afternoon snack in the sun! ■

Dr. Michael Goldberg,DVM, DCHom, Hudson Place Veterinary Clinic, (604)266-2731, Vancouver, mikepetvet@telus.net or www.hudsonplacevetclinic.com.

Dr. Goldberg practises holistic veterinary medicine, specializing in classical homeopathy. Chiropractic and acupuncture are also available through his clinic. He lives in Vancouver with his wife, Ronee, three daughters, a fourteen-year-old Border Collie, a four-month old Great Pyrenees, and three cats.


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Comments (9)

I have a two year old female boxer who has enjoyed eating grass (particularly crabgrass) since she was around a year old. She doesn't throw up and it has not appeared to hurt her...she takes great pleasure in it! I'm wondering though which vegetables I could cook for her as I think she would enjoy something different than her dog food She is on a very good high quality food, but maybe she thinks something is lacking.
Wed, 11/14/2012 - 07:34
My two chihuahuas have excellent kibble which is left out for them. Obviously, the hunger theory as a reason for grass eating does not apply to my dogs. Plus, they'd have to eat a lot of grass ti lessen their hunger. They eat crab grass. I have tasted a morsel of it and it has a scratchy surface which for me is very yucky. I do not detect any flavor whatsoever. So for my dogs, they like to graze on this every day for some other reason. They prefer they tender tips. I believe it may help their digestion or, perhaps it actually is tasty to them. They receive fresh veggies at home: when we eat peas or beans, they get peas or beans. When we eat brocolli, they get it as well as fruits, etc. They are not interested in lettuce of any kind. I don't know, of course, why crab grass might aid in digestion. It would be extremely interesting to know -- I wonder if any scientist has done a study on this.
Sun, 12/09/2012 - 13:30
Great article! And very informative. Here are some more reasons why your dog is eating grass. http://bit.ly/13MgQD8
Wed, 05/01/2013 - 08:59
What Homeopathic remedies are good for this situation?
Tue, 06/10/2014 - 01:28
No homeopathic remedies work for anything. They fail to distinguish themselves from the plain old placebo effect.
Thu, 06/09/2016 - 15:50
The real reason why dogs eat grass is because like humans they need vitamin B17, otherwise known as Laetrile. Certain grasses and grains that people eat in the poorest of countries contain this vitamin and when doctors did a study they found that there was NO history of cancer in these groups of third world people. Dogs and other animals seek this vitamin in grasses, seeds, berries, grains, plants, etc. because as we know, animals can get cancer. When domesticated animals like dogs eat grass instinctively this is how to stop cancerous cells from forming because CANCER IS A DEFICIENCY DISORDER and this is a FACT..The FDA, which does anything for MONEY won't approve it because BIG PHARMA want's people to spend more money on useless and horrible chemotherapy and radiation, OR surgery. Does that make sense? Submit yourself to sickening chemicals that weaken you and than submit to radiation? B17 really does prevent and stop cancer cells, the FDA did a faulty study when they gave a small sample group that were already weakened from traditional torture treatment and then only gave them tiny, partial doses far below the recommended amount...so, they deemed it ineffective and called it quackery..OF COURSE...money talks and that's how it's always been. But this is real, and I urge anyone to do unbiased research on this subject because it can save lives, even your dogs.
Mon, 07/07/2014 - 08:58
Hi I have a nine year old chihuahua and she sleeps with my parents and my mom told me that she can't sleep and her belly growls and she are grass and it happened twice this month but my mom only see her eat grass once is she ok?!!!...please help?!!
Wed, 07/23/2014 - 18:39
tummy growl huh? All I knOw about gurgly tummies with dogs is that they could have a problem with digestion. The same as people. I started feeding my dog a dog food that has a probiotic blend in it and now all those noisy stomach issues are gone. From what I knOw probiotics are good bacteria that cleans up all the bad bacteria in the digestive tract. I hope this will help.
Sat, 07/26/2014 - 13:55
Hi there, just on the subject of dogs eating grass, I have noticed them eat more grass of a young soft nature when with worms, and this grass goes strait through without digestion, I also noticed that during malting they eat coarse and young soft grass and there vomit contains course grass wrapped in hair and a couple of days later fesses contains the softer grass also with hair wrapped around it, as hair is non digestible, this could be an answer, they eat way less grass when not molting like winter time around 25 deg Celsius and more when its hot.
Sun, 01/04/2015 - 15:40

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