Lemongrass

A lemon-scented Cymbopogon grass used in cooking and essential oils. The ASPCA lists it as toxic to dogs, cats and horses; it is not cat grass, and its oil should be kept away from pets.

Is lemongrass safe for cats and dogs? Not really. The ASPCA lists lemongrass (Cymbopogon citratus) as toxic to dogs, cats and horses. A nibble of the plant usually means nothing worse than an upset stomach, but a cat or dog that eats a lot of the tough leaves can end up with a blockage, and the concentrated essential oil is a bigger concern than the plant, especially for cats. Lemongrass is not "cat grass", and it should not be diffused, sprayed or rubbed on pets.

Below: what lemongrass is, why it causes problems, the plant versus the oil versus food, cats, dogs and horses one by one, what to do if your pet ate some, and which scents and plants are better choices for a home with animals.

What Lemongrass Is

Lemongrass is a tall tropical grass, mostly Cymbopogon citratus, grown for cooking (Thai and Vietnamese dishes, teas) and for its essential oil. It is a close relative of citronella, which is distilled from two neighbouring Cymbopogon species. The lemon smell comes from citral, a pair of aroma molecules called geranial and neral that belong to the terpene family. In one 2025 analysis, geranial and neral made up about 78% of the oil (46.4% and 31.6%) (BMC Complementary Medicine, 2025).

Why It Causes Problems for Pets

The ASPCA names two toxic principles in lemongrass: its essential oils and cyanogenic glycosides, compounds that can release small amounts of cyanide when the plant is chewed. In practice, three things matter:

Stomach upset. The most common result in dogs and cats is vomiting and diarrhoea, which is what the ASPCA lists as the clinical sign for both species.
Blockage. The leaves are long, sharp-edged and very fibrous. A cat or dog that eats a quantity of them can get a wad of plant material stuck in the stomach or intestines, which is a surgical problem.
The oil. Concentrated lemongrass oil irritates the mouth, stomach and skin, citral is a known skin sensitiser in people, and cats in particular clear these compounds slowly.

Serious cyanide poisoning would need a dog or cat to eat far more lemongrass than they realistically will. The everyday risks are the stomach, the blockage and the oil.

Lemongrass Is Not Cat Grass

This is the most common mix-up. The "cat grass" sold in pet shops is young wheat, oat, barley or rye — soft, short and safe to nibble. Lemongrass looks grassy and smells pleasant, and cats are drawn to it for the same reason they chew any grass, but it is a different plant with different chemistry. If your cat likes to graze, grow a pot of wheatgrass or oat grass for it and keep lemongrass where the cat cannot reach.

Plant, Oil, Food: Form by Form

The growing plant

Low to moderate risk. Most pets that chew a leaf or two vomit once and move on. Keep potted lemongrass out of reach of cats, especially indoors, and fence it off in a garden if your dog likes to graze.

Lemongrass in food

A dog that steals a bite of a curry or a stir-fry containing lemongrass is far more likely to have a problem with the onion, garlic, salt or fat in the dish than with the lemongrass. Do not feed lemongrass deliberately, and keep the discarded woody stalks out of the bin a dog can raid — they are exactly the fibrous pieces that cause blockages.

Lemongrass tea

Not recommended. There is no benefit to a pet, and the tea concentrates the plant's compounds. A lick from your mug is not an emergency.

Lemongrass essential oil

Avoid it around pets. Do not apply it to a dog or cat, do not diffuse it in a room a cat cannot leave, and store the bottle out of reach. Most essential-oil poisonings happen when a pet gets into the bottle or is sprayed with a home-made mix, not through normal household use.

Shampoos, sprays and "natural" flea products

Lemongrass oil turns up in dog shampoos and plant-based flea and insect sprays, usually at low levels and usually blended with other oils. A rinse-off dog shampoo is a very different exposure from a leave-on spray. Read the label: many "natural" flea products made for dogs also contain oils that are dangerous for cats, so never use a dog product on a cat, and keep cats away from a freshly sprayed dog until it has dried.

Cats and Lemongrass

Cats are the most at risk, for two reasons. They graze on grass-like plants, and they handle essential oils poorly. The Pet Poison Helpline explains that cats lack a key liver enzyme needed to break down many essential-oil compounds, and its list of oils most dangerous to cats includes citrus oil (d-limonene) — and lemongrass's citrus-type aroma chemistry sits in the same family. Lemongrass oil is not one to use anywhere near a cat.

Indoors, keep potted lemongrass in a room the cat cannot get into, or not at all.
Never diffuse lemongrass in a room a cat cannot leave, and not at all around a cat with asthma.
Never put lemongrass oil on a cat, diluted or not — cats groom it straight off their coat.
Signs to watch for: vomiting, drooling, pawing at the mouth, wobbliness, or open-mouth breathing after a diffuser has been on.

Our Cat Safety entry covers the wider list of what cats process differently.

Dogs and Lemongrass

Dogs are less sensitive than cats but are more likely to eat a lot of something. The patterns vets see are a dog that grazes a garden clump of lemongrass and vomits, and a dog that eats discarded stalks from the kitchen and develops a blockage. Topically, there is no reason to put lemongrass oil on a dog; if you use a lemongrass shampoo, rinse it out thoroughly and stop if the skin reddens or itches.

Horses and Lemongrass

The ASPCA also lists lemongrass as toxic to horses, with difficulty breathing, weakness and, rarely, death among the signs. Horses do not usually seek it out, but do not plant it along a paddock fence or put cut lemongrass in with forage. Lemongrass and citronella oils appear in some equine fly sprays; use those as labelled, keep them out of the eyes and off broken skin, and patch-test a new product.

What to Do if Your Pet Ate Lemongrass

Take the rest away and work out roughly how much was eaten, and whether it was the plant, food, tea or oil.
A leaf or two of the plant: watch for 24 hours. A single bout of vomiting is common and usually the end of it.
Call your vet for repeated vomiting, diarrhoea lasting more than a day, a painful or swollen belly, straining with no stool, or refusal of food — signs of a possible blockage.
Any essential oil exposure, or a cat that ate the plant: call your vet or a pet poison line now. Do not make the animal vomit; oils can be inhaled into the lungs. For oil on the coat, wash with a little mild dish soap and lukewarm water.
Who to call: your vet, the ASPCA Animal Poison Control Center on (888) 426-4435, or the Pet Poison Helpline on (855) 764-7661. Both may charge a consultation fee.

What Scents and Plants Are Safer Around Pets?

No essential oil is risk-free for a cat, and the safest approach in a cat household is not to diffuse oils at all. For dogs, lavender and frankincense are the two most often described as lower-risk when diffused briefly in a ventilated room the dog can leave; tea tree, wintergreen, pennyroyal, pine, cinnamon, clove, peppermint and eucalyptus are the ones to keep away. If you want greenery that is safe to nibble, grow cat grass (wheat or oat), or choose plants the ASPCA lists as non-toxic to dogs and cats, such as spider plants, Boston fern, calathea and basil. Our peppermint oil entry covers the full essential-oil safety list.

Where Hemp Fits — and Where It Doesn't

Lemongrass has no role in a pet's care, and nothing on this page is a reason to buy anything. If what brought you here is a cat or dog that seems unsettled, stiff or off-colour, that is a vet conversation first. Where hemp has real evidence in dogs is joint comfort: our own 90-day study of 37 dogs with chronic joint discomfort, overseen by Dr. Robin Downing, DVM with Colorado State University researchers, found that 30 of the 32 dogs that completed it showed a benefit and 94% of owners reported an improved quality of life.

We do not put essential oils in any HempMy Pet product — the cat-safety reasons above are a big part of why. Our full-spectrum hemp seed oil is served by weight with food: the 250mg bottle ($49) for cats and dogs up to about 40 lbs, the 1000mg bottle ($99) for bigger dogs, and the 5000mg equine formula ($199) for horses. See hemp for cats, hemp for dogs, hemp for horses and the serving guide.

Frequently Asked Questions

Is lemongrass safe for cats?

No. The ASPCA lists lemongrass as toxic to cats, mainly causing vomiting and diarrhoea, and a cat that eats a lot of the fibrous leaves can develop a blockage. Lemongrass essential oil is a bigger concern than the plant, because cats clear essential-oil compounds slowly. Keep the plant out of reach and do not diffuse or apply lemongrass oil around cats.

Can cats eat lemongrass?

They should not. A small nibble usually causes no more than one bout of vomiting, but lemongrass is not cat grass and has no benefit for a cat. If your cat likes to graze, grow wheatgrass or oat grass for it instead.

Is lemongrass safe for dogs?

Not in any meaningful amount. The ASPCA lists it as toxic to dogs, usually causing stomach upset, and discarded woody stalks are a blockage risk. Do not feed it, keep garden clumps fenced if your dog grazes, and do not put lemongrass oil on your dog.

Is lemongrass essential oil safe for dogs?

Avoid it. Concentrated lemongrass oil irritates skin and the gut, and there is no benefit to using it on a dog. A rinse-off dog shampoo containing a little lemongrass is a much smaller exposure than a leave-on spray or neat oil; rinse it out well and stop if the skin reacts.

Can I diffuse lemongrass around my pets?

Not around cats or birds. Around dogs, it is better avoided; if you do use it, keep sessions short, the room ventilated and the door open so the dog can leave. Lavender or frankincense, used the same way, are generally considered lower-risk choices for dogs.

What happens if my dog eats lemongrass?

Usually vomiting or diarrhoea that settles within a day. Call your vet if the vomiting repeats, the belly is painful or swollen, the dog strains without passing stool, or it refuses food — those suggest a blockage from the fibrous stalks. Any exposure to the essential oil is a reason to call straight away.

Is lemongrass the same as citronella?

No, but they are close relatives in the same Cymbopogon genus and share similar aroma compounds. Both are listed as toxic to pets by the ASPCA, and both are common in bug repellents. Our citronella entry covers that plant in detail.

Is lemongrass safe for horses?

The ASPCA lists lemongrass as toxic to horses, with difficulty breathing and weakness among the signs. Do not plant it by a paddock or add cut lemongrass to forage. Equine fly sprays containing lemongrass oil should be used as labelled and kept out of the eyes.

What scents are safe for cats?

No essential oil is fully safe for cats, and the safest choice is not to diffuse oils in a cat household. If you want a pleasant-smelling home, ventilate, use unscented cleaning products, and choose cat-safe plants such as cat grass, spider plants or Boston fern. Keep citrus, pine, tea tree, eucalyptus, peppermint and wintergreen oils away from cats entirely.

What smells do cats hate?

Cats commonly dislike citrus, eucalyptus, peppermint, vinegar and strong spices, which is why citrus peels and sprays are sold as deterrents. Several of those, as concentrated oils, are also unsafe for cats, so use them only as diluted, cat-free deterrents outdoors, never sprayed on or near the cat.

Is lemongrass a flea repellent for pets?

Some natural flea and insect products use lemongrass oil, but there is no good evidence that it protects pets from fleas or ticks reliably, and leave-on oil products carry their own risks, especially for cats. Ask your vet for a proven flea and tick preventive suited to your pet's species and weight.

Written by Marc Brannigan, Co-Founder & CEO of HempMy Pet. Marc co-founded HempMy Pet in 2016 with his business partner Natalie Mondine, the company's COO. HempMy Pet breeds its own hemp genetics, grows them on its certified-organic Colorado farm, and formulates every batch in-house under human-grade standards. Every batch is third-party tested, and the company's 90-day dog study was overseen by Dr. Robin Downing, DVM, MS with Colorado State University researchers. This entry is general information, not veterinary advice. Last updated 19 October 2026.