How to Stop Your Dog From Eating Grass and Throwing Up

First, Is It a Problem?

A dog that nibbles a few blades of grass on a walk and continues normally is doing something dogs have done since they were wolves. It’s not weird and not necessarily a sign of anything wrong. The behaviors actually worth addressing are:

• Frequent vomiting after grass-eating (more than once a week)
• Frantic, urgent eating — gulping mouthfuls instead of casual grazing
• Eating grass to the exclusion of food they normally like
• New behavior that wasn’t there before
• Eating grass in places with pesticides, herbicides, or other dog poop nearby

If your dog grazes occasionally and seems fine, you can usually let it go. The rest of this article is for the cases where it’s actually a problem.

Why Dogs Eat Grass

There’s no single answer, and the old “dogs eat grass to settle their stomach” story is only partially true. Studies show:

• Most dogs that eat grass don’t throw up afterward — only about 25% of grass-eating ends in vomiting.
• Dogs that eat grass aren’t more likely to be sick than dogs that don’t, on average.
• Vomiting from grass usually isn’t intentional — the grass irritates the stomach, but most dogs don’t seem to be seeking that out.

The actual reasons fall into a few buckets:

Boredom or under-stimulation. Grass is interesting. It moves, smells, and provides chewing satisfaction. Dogs that don’t get enough physical or mental exercise often invent activities, and grass is convenient.

Genuine nausea or GI discomfort. Dogs that already feel sick do sometimes seek out grass, and the frantic version of grass-eating points here. Causes range from minor (ate something weird) to serious (pancreatitis, IBD, intestinal blockage).

Hunger or feeding schedule issues. Some dogs graze when their stomach is empty for too long, especially in the morning before breakfast.

Pica (eating non-food items). A pattern of eating dirt, rocks, fabric, and grass can indicate nutrient deficiency, anxiety, or compulsive behavior.

Taste preference. Some dogs just like the flavor of certain grasses. Mowed lawn smell after rain attracts a lot of dogs.

Anxiety or compulsive behavior. Like licking, pacing, or excessive grooming, grass-eating can be a self-soothing behavior in stressed dogs.

What’s Actually Going Wrong When They Throw Up

Grass blades have rough edges and silica content that irritates the stomach lining. When a dog eats more than the stomach can comfortably hold, or eats it quickly, the stomach responds by pushing it back up — usually within 5-30 minutes.

The vomit is typically:

• Yellow or clear bile mixed with grass
• Foamy or slimy
• Contains undigested grass blades
• Followed by the dog acting completely normal afterward

Occasional vomits like this in an otherwise healthy dog aren’t a crisis. What you don’t want is the pattern: eat grass → throw up → eat grass → throw up. That cycle suggests the dog is using grass as a self-medication for ongoing nausea, and you need to find out why they’re nauseous in the first place.

When to See the Vet

Don’t write off grass-eating + vomiting if any of these apply:

• Vomiting more than twice in 24 hours
• Vomit contains blood, looks like coffee grounds, or has a foul smell
• Dog is lethargic, off food, or seems depressed
• Diarrhea on top of the vomiting
• Hunched posture, painful belly, or whining
• Sudden onset in a senior dog
• Suspected exposure to pesticides, fertilizers, or chemicals
• Possible foreign body ingestion (string, toys, socks)

For the rest — occasional grass + occasional vomit in a normal-acting dog — you can address it at home.

How to Actually Stop the Behavior

Five things, in order of how likely they are to work:

1. Increase Physical and Mental Exercise

Bored dogs invent jobs. The single most effective change for casual grass-eaters is more genuine activity. Not just “we walk for 20 minutes” but:

• Sniff walks — let the dog stop and sniff things. The mental stimulation tires them out more than fast pace.
• Puzzle feeders — make them work for breakfast and dinner.
• Training sessions — 10 minutes of teaching new commands counts as exercise mentally.
• Off-leash time in safe areas if possible.
• Tug, fetch, or chase games in the yard before walks.

A dog that comes home tired stops looking for things to chew, including grass.

2. Adjust Feeding Schedule

If your dog eats grass first thing in the morning or before meals, they may be experiencing bile reflux from an empty stomach. Try:

• Splitting meals — instead of one big meal, feed two or three smaller ones spaced out.
• A bedtime snack — a small piece of plain food or a few kibbles before bed prevents the stomach from being empty for 12+ hours.
• Elevated feeding — for some dogs, eating from an elevated bowl reduces post-meal reflux.

3. Train a Reliable “Leave It”

This isn’t a one-day fix, but it’s the long-term solution for outdoor grazing. Practice “leave it” with low-value items first (a treat on the floor), build up to higher-value distractions, and eventually use it on walks.

The framing that works best: “leave it” isn’t about denying the dog something — it’s a cue that means “look at me and you’ll get something better.” Pair every successful “leave it” with a high-value treat from your pocket.

For dogs that absolutely cannot resist grass, a head halter (Halti or Gentle Leader) gives you steering control on walks and makes “leave it” easier to enforce.

4. Provide Safe Alternatives

If your dog has a real urge to chew greens, give them options that aren’t lawn:

• Green beans (fresh or frozen, no added salt) — most dogs love these
• Carrots — raw, in chunks, double as a chew
• Cucumber slices
• Lettuce or spinach in small amounts
• Broccoli (small amounts; can cause gas)
• Wheatgrass or pet grass — deliberately grown indoors for cats and dogs to nibble safely

Pet grass is especially useful for dogs that genuinely seem to crave the texture. Buy a tray, put it where they can reach it, and they’ll often graze that instead of the lawn.

5. Address the Anxiety Component (If Relevant)

Grass-eating that increases when you leave for work, during thunderstorms, or after household changes is anxiety-driven. The fix isn’t to stop the grass-eating directly but to reduce the anxiety:

• Predictable routine — meals, walks, bedtime at consistent times
• Enrichment — Kong with frozen peanut butter, snuffle mats, lick mats
• Calming aids — Adaptil diffusers, calming chews (talk to your vet first)
• Behavior support for severe cases — a vet behaviorist or anti-anxiety medication can break the cycle

What to Skip

A few things people commonly try that don’t help:

• Punishment. Yelling or correcting a dog after they’ve eaten grass doesn’t connect to the behavior in their mind, and it can make anxious grass-eating worse.
• Vinegar or hot sauce on the lawn. Dogs ignore it, and you’ll damage the grass.
• Fertilizing the lawn to “make it taste worse.” Lawn chemicals are toxic to dogs — this is the worst possible “fix.”
• Adding probiotics or supplements without a reason — they don’t address the actual cause and may not change anything.
• Restricting all yard time. Removes the symptom but not the underlying boredom or nausea.

Special Case: The Dog Who Eats Grass Then Eats Their Vomit

This combination is unsettling but common. Dogs are scavengers; eating regurgitated food doesn’t bother them. The behavior itself isn’t dangerous unless the vomit contains something that shouldn’t go through the stomach twice (sharp objects, toxins).

The fix: clean it up before they get to it, address the underlying cause (so vomiting stops happening in the first place), and don’t punish — that adds anxiety to an already-stressful situation.

Quick Diagnostic Flow

Pattern	Likely cause	First move
Casual nibbling, no vomit, normal otherwise	Curiosity/boredom	Increase exercise, accept it
Occasional grass + occasional vomit	Mild GI irritation	Adjust meals, add fiber
Frantic grass-eating, then vomit	Active nausea	Vet visit
Eats grass + dirt + rocks	Pica	Vet workup, possible nutrient deficiency
Increased after household change	Anxiety	Address stressor
Sudden new behavior in senior dog	Possible illness	Vet visit

The Bottom Line

A dog that nibbles grass occasionally is being a dog. A dog that eats grass frantically and throws up regularly is telling you something — either they’re nauseous, bored, anxious, or missing something nutritionally. Address the cause and the grass-eating usually fades on its own. Vet visit if it’s new, severe, or accompanied by anything else.

For more on dog GI health, see our bland diet guide for diarrhea, the dog poop color chart, and the why dogs follow you post if anxiety might be playing a role.