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Why Dogs Eat Grass and Other Weird Things

Schatzie has bachelor's degrees in animal science and English and a master's in education.

Your dog ate grass again? Why?

Your dog ate grass again? Why?

Your Dog Ate What?

Over the years, my family and I have owned several dogs, and at some point or another, each has exhibited what we would consider odd behavior.

There were our two cockapoos, Mandy and Emmy, who were often chased around the backyard by my enraged mother as they dared to not only nibble upon her coveted heirloom tomatoes but also trample her flower beds in the process.

As each tomato harvest neared, it was an almost nightly occurrence to hear “Mandy, you bad, bad dog!” and have our plump pooch appear at the screen door, beard tinged green with tomato vine juices, begging to be let in and escape her wrath. And, while eating tomatoes on its own might not be considered too strange, the lengths to which she would go to get at them was quite impressive: systematically digging under and bravely leaping over various barriers of ever increasing size and height.

Then there was Chui who, as you guessed it, chewed on everything. One night she got a hold of my sister’s lipstick and ate up the entire tube. It was obvious who the culprit was anyway, but the “dusty rose” hued paw prints exiting the bathroom and leading straight to the dog bed eliminated any and all doubt. Though this could have been in retaliation for my sister and I pinning her down a mere few days earlier and coloring her head fur in alternating shades with highlighters as a type of faux hawk, but what could have inspired her to taste and then consume chemical laced wax was beyond us.

She also ate grass…true, my most vivid memory of her doing so was after feeding her an entire block of cheddar cheese as a six-year-old’s “how much cheese can my dog eat?” type experiment, but it was still an unusual sight to see her grazing in the backyard like a cow. At least I had my answer to my question: nearly all the newly purchased cheese was gone, and in its place was a large puddle of bright green vomit. Remember, I was six!

Then there is Mahi, our English Labrador. You often don’t know what she has devoured until it comes back up, soaked in noxious bile. We don’t even see her doing the throwing up, we just step upon something wet and find a soggy yellow half-devoured remnant of something or other under our foot. Socks, paper towel, or her ultimate favorite—baby wipes. When the baby needs a diaper change, Mahi is the only one who finds this concept exciting.

She’ll creep stealthily into the nursery when you’re busy doing the changing and then the minute you throw a wipe into the garbage bin, she pounces and in a flash it is gone, swallowed whole down her greedy gullet. It is literally so instantaneous that I sometimes believe I simply imagined the whole thing…until I’m walking around the next morning and trod upon something slimy. Pull out a wipe to mop up spit up, clean off a toy, whatever, and put it down wherever and she is there, waiting. Watching. You’ll reach for it in the exact place you last put it, and you’ll grasp air.

So why is it that dogs eat things such as tomatoes, lipstick, grass, and baby wipes, and with great gusto I might add, despite being fed a good amount of high quality dog food? Why would they bound over fences, dig through mud, and knock over furniture as large as they are to get to these strange treats?

There are a few theories out there that attempt to answer this question.

The Modern "Wolf"

One focuses on a simple truth: our dogs are not going to act a certain way because we have decided that they should. The domesticated dog is a direct descendant of the wolf, and therefore before we label a pet’s behavior as “strange,” “unusual,” or even “harmful,” we must realize that it may be acting in accordance with characteristics retained from its wild, savage, and free-roaming genetic ancestry. Bottom line: there may be urges that our dogs have nutrition-wise or behavior-wise that can be satisfied in nature but which are not provided for in our modern, human-oriented worlds.

So, with this in mind, why would a dog eat something like grass? Well, why wouldn’t it? A study of the wolves in Yellowstone National Park revealed that their summertime diet frequently included vegetation (The wolves were pure carnivores in the winter, but can you blame them for not wanting to dig through snow and ice to get calorie-sparse twigs at a time when energy conservation is tantamount to survival?) (1). It is worth noting that though the ingestion of prey species is considered purely carnivorous, when wolves devour a kill whole they also consume its stomach and the roughage-rich meal within it.

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To survive, wild wolves are opportunistic feeders and will eat fruits (tomatoes are fruits!) and berries…even insects and reptiles when other foods are scarce (2). This scavenging, eat-when-food-is-available instinct can still be seen in the modern dog. Mahi’s veterinarian claimed that she would literally eat herself to death if given the chance, and I never fail to be amazed at the voracity with which Mahi attacks road kill or various barely-edible items littering her path even minutes after enjoying a hearty meal, complete with a bacon Beggin’ Strip dessert.

She is not the only one--look around on your next trip to the dog park at the rolly polly pooches barely able to support their plump bodies on their (by comparison) iddy biddy spindly legs. Our dogs may eat strange things just for the sake of eating, urged to chew and swallow by a subconscious need to consume as many calories as possible, when possible, to “survive” when such behavior is no longer necessary or appropriate.


Wolves don’t have the luxury of being served breakfast, lunch, and/or dinner in a clean dish and washing it down with fresh water from a neighboring bowl like our pampered pets. Instead, they travel miles and miles in search of sustenance. Some packs are known to roam over 30 miles in a single day! (3). Now, contrast this 30 mile figure to the amount of exercise you give your pooch. I’m guessing your daily regimen is seriously lacking in comparison. Not that that is necessarily a problem…

After all, dogs, though related, are not actually wolves. Most do not have the same endurance (I once petsat a mini dachshund that would find running the length of the room, tiny little legs pumping a mile a minute, exhausting enough) but most do have the same innate need to run, jump, and sprint on a daily basis for optimal health and energy release. And whereas domesticated dogs also do not (hopefully) need to actively search for hours upon hours for their next meal, that does not mean that the drive to seek out, chase, and devour prey has vanished either. Just ask your neighbor with the cat.

Which brings us to a possible explanation of why you dog may devour the seemingly “inedible” things left lying around: boredom. Without running around looking for food, and once finding it, throwing itself into the thrill of the hunt and chase, the dog has to fill up its free time somehow.

And if its owner is out working or zoned out in front of the TV, pizza in one hand and a beer in the other (in other words not going anywhere anytime soon), tearing apart a discarded sock or snacking upon a stick of lipstick is far more entertaining than the alternative: lying around doing nothing. A dog still requires physical and mental stimulation and it knows how to find it when it’s not provided!

Nutrient Deficiency

Then there is the theory that focuses on a different problem: an imbalanced diet.

The dog caught grazing on the lawn may suffer from a lack of dietary fiber. Ideally, pet foods should contain a total of 2-4% (4). Less than this and your dog will need to supplement by nibbling upon your backyard greens…or suffer chronic constipation. Then again, foods with levels over 10% can do more damage than good, creating larger, more frequent stools and leading to flatulence…not a good thing for the dog…or the humans in the nearby vicinity (4).

Similarly, things such as baby wipes or diaper rash cream (yes, I have also found Mahi, snout stuck in the A&D jar) often contain various vitamins or minerals which a dog may need or be deficient in. Aloe vera juice, the second ingredient in Pampers Sensitive Wipes, has vitamins A, C, E, B12, folic acid, and choline and 9 minerals including calcium, potassium, and zinc (6). Lanolin, the main ingredient in the A&D diaper rash cream, is a great source of vitamin D-3. In fact, lanolin is often recommended as an alternative supplemental source for people allergic or intolerant to fish oil and who need more of the vitamin in their diet (7, 8).

Both products, though hardly palatable to you or I, do have important nutrients that may make them a highly desirable snack to a dog. (This may also explain why after I apply deodorant, sunscreen, or any type of moisturizing lotion with various vitamin-based skin-softening ingredients I have to literally run out the door or be licked clean).

Even lipsticks contain various waxes, oils, and fats (as well as lanolin) that a dog might need. Beeswax, a very common cosmetic additive, is used medicinally by individuals who want to reduce their cholesterol levels, fight pain, minimize inflammation, or cure diarrhea (9). It just may be similarly helpful to a pooch. And humans are not the only ones who benefit from consuming olive oil, also sometimes present in lipstick and chock full of both omega 6 and omega 3 fats.

So was Chui’s ingestion of my sister’s makeup revenge? Probably….as eating an entire block of cheddar cheese most likely set her up to satisfy her fat requirements for life. But possibly not.


Then there is the theory we all dread: that our dogs perform strange behaviors due to some underlying medical condition or ailment.

Let’s again address the grass eating canine, whose behavior most attribute to a need to regurgitate and empty the contents of an upset stomach because they are “sick”.

Believe it or not, although most people think that they should dogs do not usually throw up after eating grass (a practice which, in addition to wolves, is frequently seen in wild dog populations). In fact, less than 25% of dogs vomit and fewer than 10% look unwell before ingesting greens, according to certain studies (10).

Could the dog be eating grass because it has some sort of non-obvious affliction, such as an internal parasitic infection? Well, again, if dogs are trying to eat grass to expel parasites from its body and they fail to vomit, they also fail in the expelling. What about the other direction, you may wonder (via the feces). It’s possible. But it’s far more likely that they get infested by eating contaminated grass than that they cure a present infestation with grass eating.

The experts seem to believe that routine grass eating of clean, chemical-free lawns is okay and normal, but only if the dog does not throw up. Some even believe that dogs simply like the flavor or texture of grass (11). I’m sure Chui enjoyed the flavor of the cheddar cheese (as do I) and perhaps Pampers wipes or diaper rash cream are similarly yummy, to a dog…I will not be determining how good they do or do not taste myself.

Is Odd Behavior Dangerous?

Odd behavior is not necessarily dangerous behavior or indicative of a serious problem. Experts do warn, however, that sudden changes could be a cause for concern. Did your dog abruptly, out of nowhere, for the first time in its life gobble down a large amount of grass and then vomit repeatedly? Did your dog who’s usually calm and well-behaved suddenly knock over and eat all of your cosmetics in one sitting? A veterinarian’s opinion as far as whether there may be an actual issue, whether one of a physical or psychological (stress, anxiety, etc) nature, is recommended in such instances.

And, of course, making sure that whatever your pet did eat isn’t toxic is always a good thing to do…The ASPCA website has a listing of foods dangerous or toxic to pets that is worthwhile reading. And, if in doubt, don't hesitate to call and ask your veterinarian. You may feel silly asking questions such as "Will my dog be seriously ill since she just half-ate a dirty diaper?" but, knowing what dogs are capable of, I'm sure they've pretty much heard it all.

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

Got any Strange Pet Stories to Share?

Schatzie Speaks (author) on July 31, 2019:

Dogs and cats both do the strangest things! Some might not be too funny at the moment, but they sure are after!

Patricia Scott from North Central Florida on July 26, 2019:

I had to laugh at some of these behaviors...because they reminded me of behaviors of my little polydactyl kitty that used to live with me. Angels are on the way today ps

Maggie Griess from Ontario, Canada on October 13, 2015:

Amusing about the tomato eating; my dog decided to grab a tomato off a low shelf and I found her tossing it funny I forgot to scold her! :)

Kristen Howe from Northeast Ohio on March 31, 2015:

Thanks for sharing your story, Schatzie. They sounds like lovely dogs. Voted up!

flint3099 on March 06, 2015:

My dog loves getting into the litter box and eating those "kitty cookies". We have to put the litter box up high so that she can't get into the box. Makes no sense why she enjoys doing that.

Schatzie Speaks (author) on November 18, 2014:

oh no, he eats the cat poop?! though with a name like "kitty cookie" it almost sounds appetizing haha. and, it's kind of doing you a favor, you won't have to change the litter box as often, right? :P

Bill from Greensburg Pennsylvania on November 18, 2014:

Mine likes the kitty litter box. I call them kitty cookies. Can't stop him. I don't know how many times he has been yelled at for it.

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