If you’ve ever spotted your dog munching on grass during a walk or in the garden, you’re not alone. This quirky canine behaviour puzzles many pet parents. Is it instinct? Boredom? Or is your dog trying to tell you something? While the occasional nibble is usually harmless, understanding why dogs eat grass can offer useful insight into their wellbeing.

Instinctive Behaviour from Their Ancestral Roots

Dogs are omnivores by nature. Long before kibble and cold-pressed raw patties, their ancestors roamed and scavenged. Grass and other plants were part of their natural diet, either consumed directly or incidentally through the stomach contents of herbivorous prey.

“We believe dogs may have inherited the tendency to eat grass from wild canids like wolves and foxes, who often consume plant material as part of a balanced diet,” says Dr Charlotte Baldwin, a canine behaviourist and veterinary consultant.

A Sign of an Upset Stomach

One of the most popular theories is that dogs eat grass to make themselves sick. And yes, some dogs do vomit afterwards. But research has shown that most dogs who eat grass aren’t unwell beforehand, and only a small percentage actually vomit.

“Grass eating may help some dogs soothe a mild gastrointestinal irritation, but in most cases, it’s not about being sick—it’s more about the act of eating,” explains vet nurse Louise Hammond.

They’re Simply Bored or Curious

For many dogs, nibbling grass is just something to do. Especially for young, energetic dogs or those left alone in the garden, eating grass can be a form of entertainment. If your dog doesn’t seem stressed or unwell and you’ve ruled out dietary deficiencies, boredom might be the cause.

Offering mental stimulation through puzzle feeders, long walks, and rotating toys can help redirect this behaviour.

It Could Be a Nutritional Gap

Some experts believe that grass-eating might be linked to a dietary deficiency, often fibre. A dog on a low-fibre or heavily processed diet may instinctively seek out roughage. Switching to a more natural, balanced diet can make a difference.

“In some cases, dogs eating grass may be trying to meet a biological need,” notes holistic vet Dr Eleanor West. “If the behaviour decreases after switching to a diet rich in whole foods and fibre, it’s a clue.”

At Poppy’s Picnic, all our raw dog food recipes—like our RAW POWER Beef Mince for Dogs—are naturally rich in nutrients and designed to support digestive health, which can reduce the urge to snack on grass.

When Should You Be Concerned?

Grass-eating in itself isn’t usually dangerous, but there are times to be cautious. If your dog is eating grass obsessively, seems distressed, vomits frequently, has diarrhoea, or shows signs of lethargy, it’s best to speak to your vet. Also, keep an eye out for treated lawns—pesticides and weed killers can be harmful if ingested.

“It’s important to assess the full picture,” says vet Dr James Archer. “One-off grass eating isn’t a red flag, but persistent behaviour coupled with other symptoms warrants a check-up.”

What Can You Do About It?

If your dog eats grass occasionally and shows no other symptoms, you likely don’t need to intervene. However, if it’s becoming a habit, try the following:

• Review their diet to ensure it’s complete and balanced

• Provide enrichment through games, sniff walks, or training

• Make sure they have access to clean, safe grass if they want it

• Monitor for any signs of illness or digestive issues

Final Thought

Grass eating in dogs is a common behaviour with several possible causes—from instinct to boredom, from dietary needs to the simple joy of chewing something green. Most of the time, it’s nothing to worry about. But if you’re ever unsure, trust your instincts—and your vet.