Aug 2, 20215 min read

Why Dogs Eat Grass

Do you find yourself wondering some days if your carnivorous beast is actually part cow? Does your dog love to graze on fresh summer grass while on walks or in the backyard?

Your dog may even eat grass and then vomit it back up later so, why do they do this?

While grass eating can seem like a weird behaviour and totally out of the norm for our dogs, there are actually quite a few reasons they can enjoy doing this, and it's not always cause of concern as you may think.

Reasons people think their dog is eating grass include:

1. Something is missing from the diet

2. They have an upset stomach and want/need to vomit

3. They are bored and/or anxious

4. They have a condition known as "Pica"

This can be controversial in the dog world but there IS evidence to show that grazing plant matter (they also eat plant matter via the stomach content of prey) is a natural behaviour in wild dogs, such as wolves. Plant consumption is actually not usually associated with gastrointestinal illness but instead may be a trait inherited from their wild ancestors. In a research study following the presence of plant matter in wild dog's fecal samples, it was found that:

"Evaluation of scats and stomach contents of wild canids indicate that they regularly ingest plant material, especially grass. Such studies report the appearance of plant matter in about 11% of samples of Latvian wolves (Andersone and Ozolins, 2004) and approximately 74% of samples collected in the summer from grey wolves reintroduced to Yellowstone National Park (Wyoming, USA) (Stahler et al., 2006). In studies where specific plant types were identified, grass was found in 2–3% of the samples of timber wolves (Mech, 1966), 10% of samples in Latvian wolves (Andersone, 1998) and 14% of samples from Greek wolves (Papageorgiou et al., 1994)."

Reason 1: Something is missing from their diet

The most common question I get when owners have a grass-grazer and what often comes up with a quick google search is "Is something missing from their diet?" And while a valid concern, this usually isn't the case.

People often relate grass eating to a lack of fibre. The majority of pet owners are feeding a kibble diet, which is heavy in carbs and plant matter and actually have MORE fibre than is naturally required for your dog, so lack of fibre is rarely an issue for most dogs, unless they are following a meat/bone/organ ONLY raw diet. *If your dog is showing signs of constipation such as straining or having very white, hard, crumbly stools then we should consider adding in more healthy fibre content.

Reason 2: They have an upset stomach and need/want to vomit

Often times when owners notice the grass eating behaviour they also note that the dog vomited shortly after, which leads to the assumption that they ate the grass because they felt sick and wanted to throw up. However, there are currently no research linking grass eating to feelings of unwell or wanting to vomit. Studies that have been preformed on this topic actually find that grass eating is a common behaviour and more often than not is NOT assosiated to a dog feeling unwell. It seems common, but this study concluded that less than 25% of dogs actually vomit after eating grass.

Some people also agree that dogs simply do not have the conscious ability to know how to intentionally make themselves vomit by eating grass so this would not be the case however, in my opinion, a dog could begin to relate grass eating to vomiting by association if they repeat the behaviour of feeling sick, then they happen to eat grass, then they vomit. If this sequence is repeated then the dog can begin to associate the two behaviours.

Reason 3: They are bored and/or anxious

Bored dogs can resort to grass eating in the same sense that a bored dog will chew shoes or other things they shouldn't. They simply need a better outlet for their energy and are seeking ways on their own to get it out. Bored dogs can also relate this to getting attention (remember, to a dog ANY attention, good or bad, is still attention!) if every time they start eating grass you run over to stop them. They now KNOW this behaviour gets your attention and when left to their own devices they will do it because they know it gets a reaction.

For anxious dogs, just like repetitive licking or chewing can be decompressing, grass eating can become a compulsive soothing behaviour. Anxious dogs may eat grass as a sort of mindless comfort, in the same way some people chew their finger nails.

To prevent either of this problems, ensure your dog's physical AND mental needs are being met on a daily basis which includes regular proper exercise and appropriate means for chewing/mental stimulation such as their own toys, bully sticks, raw meaty bones and kongs.

Reason 4: They have a condition known as "Pica"

This condition is actually thrown around quite a bit but in reality very few dogs have actual cases of Pica.

In humans, the condition is a compulsion to consume items that are not edible. Pica can drive people to eat things like rocks, dirt and anything else they should not eat. When diagnosing this condition in people it's often linked to a mineral deficiency which leads to the assumption that the same is true for our dogs. However, as we discussed, this is a rare solution to the problem and more often your dog is doing this for other reasons and they do not actually have Pica. Dogs that truly have Pica will consume more than just grass and will not just chew inedible objects but actively seek to consume them and put themselves in danger doing so.

And lastly, sometimes, the simplest answer is the best. While we may never fully understand this behavior, the current leading explanation is that they may actually just enjoy eating grass! Owners often notice the grazing start with fresh spring grass and this leads us to believe that some dogs just really enjoy the texture and flavour!

Read more about Pica in dogs here.

All in all, there is nothing wrong with letting your woofer graze away like a happy little goat!

There are times when grass eating becomes an issue including:

- Your dog is vomiting after eating grass daily or multiple times a day

- They are eating grass and refusing their regular food

- The behaviour starts out of no where and is constant

- They immediately begin eating grass any time they are let outside

If your dog shows any of the above it may be time for a check up with your trusted Veterinarian team to ensure nothing medical is going on.

There are also some safety concerns when it comes to eating grass as well. I only recommend letting your dog graze on grass that you know it safe and untreated with chemicals or pesticides. Unfortunately it is still common practice for the city to spray our parks and trails with chemicals that can make your dog really sick and you also don't know what other people are using on their yards when you're visiting or walking by. Always carry your dog's favorite reinforcer (treats/toy) on walks so that you can quickly redirect them when they go for a lawn snack!

Bonus Tip: For woofers that really love to graze and sniff grass, consider making them a dog-safe sensory garden for them to nibble and enjoy! We have a planter on our deck that has herbs and plants that the dogs love to graze, sniff and rub on!