Why Do Boxer Dogs Eat Grass?

If your Boxer is munching on the occasional blade of grass, it’s unlikely to be a sign anything is wrong.

Grass eating is a common behavior in dogs, including wolves.

Contrary to popular belief, it’s only rarely associated with a dog feeling sick, and doesn’t ordinarily lead to vomiting.

Perhaps the most plausible explanation for grass eating is that it’s a hangover from a behavior that served dogs well in the past: eating grass as a form of roughage to help expel intestinal parasites.

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Reasons A Boxer Dog Might Eat Grass

There is no one definitive answer as to why dogs eat grass.

Various theories put forward to explain grass eating include:

  • A response to nausea, designed to prompt vomiting in order to purge the stomach and resolve digestive upset
  • Dietary supplementation in response to nutritional deficiency, especially lack of fiber
  • Consumption of indigestible matter or roughage to expel intestinal parasites
  • Pica disorder (Compulsively eating non-food items)
  • Boredom
  • Scent concealing

There is not a lot of hard science to support any of these.

Here’s what is known.

Grass In Response To Nausea

A 2008 study conducted at the University of California, Davis concluded grass eating was normal behavior for dogs.

68 per cent of owners in the study observed their dogs eating grass on a daily or weekly basis.

It was not usually accompanied by signs of illness (8% of instances of grass eating) and only infrequently followed by vomiting (22%).

There is one standout exception to this.

A classic sign of acid reflux or gastro-esophageal reflux disease (GERD) is trying to eat leaves and even specks of dust on the floor.

If you observe grass eating in combination with drooling, neck stretching, jaw snapping, restlessness or compulsive air licking, consider whether your Boxer may be experiencing acid reflux.

Grass As A Source Of Fiber?

Since dogs are unable to digest grass, they’re unlikely to obtain much nutrition from consuming it.

The UC researchers noted that dogs whose diets included plants (vegetables or fruit) were just as likely to eat grass as dogs eating no plants.

They interpreted this to mean grass eating was not connected to dietary deficiency.

What about fiber deficiency?

A 2007 a case study of a single Miniature Poodle with a history of daily grass eating followed by vomiting found the dog ceased the behaviors as soon as he was switched to a high-fiber diet.

However, as “facultative” carnivores (animals that primarily eat meat but which can survive on plants when prey is scarce), dogs are designed to get most of their fiber from animal products.

Bones, collagen, cartilage, hair and skin are all sources of dietary fiber in the canine diet, playing the same role as vegetable fiber in the human diet.

Fermentation in the large intestine converts these animal products into short chain fatty acids, which improve the health of the cells lining the gut.

So, a Boxer eating a properly home-prepared raw diet containing plenty of raw meaty bones is unlikely to be short of fiber.

Kibble-fed Boxers, Boxers eating home-cooked meals devoid of bone and Boxers eating processed or pre-made raw grinds without enough bone and cartilage may be a different story.

Grass As Roughage To Expel Parasites

If your Boxer eats grass, you’ve likely seen it come out still intact.

But that doesn’t necessarily mean your dog has derived no benefit from its passage through the digestive tract.

Wolf droppings have been observed to regularly contain grass.

In these wild dogs, grass eating is understood to be a natural means of purging intestinal parasites.

It’s thought the fibrous matter increases intestinal contractions and “sweeps out” worms.

Grass eating may persist in domestic dogs either as an instinctual response to parasites, or as a hangover of a behavior that’s no longer strictly necessary but which has become hardwired.

There are other examples of things dogs still do as a result of those behaviors having been so evolutionarily helpful: dogs still circle before lying down even though they no longer need to flatten a bed in the long grass.


Grass eating is so common in dogs of all breeds that it’s unlikely to be the rare disorder pica, characterized by the consumption of non-food items.


Grass eating, like barking and tail chasing, can arise out of boredom, frustration or as a form of self-stimulating play.

Take it as a sign your Boxer needs more attention, exercise, play or mental stimulation.

Canine enrichment toys like puzzles such as the Nina Ottosson DogTwister Interactive Game

and snuffle mats like the STELLAIRE CHERN Nosework Feeding Mat can go a long way towards occupying your Boxer doing something constructive and preventing problem behaviors.

Some Boxers can entertain themselves for hours with a tree-tethered bungee such as the LOOBANI Outdoor Bungee Hanging Toy.

The Wobble Wag Giggle Ball, As Seen On TV is a consistent winner with Boxers, for its erratic roll and quirky noises.

Alternatively, you might try teaching your Boxer some tricks or brushing up on some obedience training.

If the grass eating is happening while you’re out, it may be time to rethink how you’re setting your Boxer up for a good day while you’re out.

Poop eating can be another sign of a Boxer lacking enough mental or physical activity, although there are many other causes.

Scent Concealing

There’s a theory that dogs eat grass to mask their own smell, just as they roll in strong scents.

As hunters, it’s important for dogs to be able to sneak up on their prey without the breeze giving them away.

While your Boxer mightn’t get the chance to catch her own dinner, this instinctive behavior may still be strong.

Hazards Associated With Grass Eating

The main reason to stop your dog eating grass is if it might be sprayed with weedkiller or treated with lawncare chemicals.

If your Boxer is eating grass on roadsides, in publicly maintained parks or on a neighbor’s nature strip you probably want to put a stop to it.

These areas are often contaminated with herbicides.

But if your dog is sampling grass in the backyard at home and you know it’s chemical-free (and not a poisonous variety), it’s usually fine.

Other Plants You Can Feed Your Boxer

As mentioned above, dogs are facultative carnivores which means means they prefer meat, but can maintain themselves on a secondary food in lean times.

In the wild, this secondary food is fruit.

The Voyageurs Wolf Project, following gray wolves in Northern Minnesota, discovered berries make up as much as 83 per cent of the diet for a whole month at the height of summer.

In August 2017, Voyageurs researchers observed an adult wolf regurgitating berries for pups.

As part of a natural canine diet, you can feed your Boxer a range of fruit such as:


Grass eating is often assumed to mean a dog is unwell and trying to induce vomiting.

In the case of acid reflux, it can certainly be a sign of intestinal upset.

More often, occasional grass eating is natural canine behavior, no cause for concern and even potentially beneficial.

Just make sure the grass is herbicide-free.


Byeong-Teck Kang et al, A high fiber diet responsive case in a poodle dog with long-term plant eating behavior, Journal of Veterinary Medical Science, 2007

S. Depauw et al, Fermentation of animal components in strict carnivores: a comparative study with cheetah fecal inoculum, Journal of Animal Science, 2012

Thomas D Gable et al, Weekly Summer Diet of Gray Wolves (Canis lupus) in Northeastern Minnesota, The American Midland Naturalist, 2018

Sueda, K L C et al, Characterization of plant-eating in dogs. Applied Animal Behavior Science, 2008