Lemongrass for Dogs: Benefits, Myths, and the Truth About Fleas and Ticks

You gave the chew you had given for years. Then something changed, and you can date it. Now the pest protection you relied on is out of your routine, fleas and ticks are still out there, and almost every plant-based option on the shelf smells like lemongrass.

Here is the direct answer. Lemongrass for dogs is really two questions wearing one name. The ASPCA lists the lemongrass plant as toxic to dogs, cats and horses, because a dog who eats a quantity of it ends up with an upset stomach. A properly diluted lemongrass oil sitting on the outside of a dog is a different question, and it has real research behind it as a flea and tick deterrent. Eating it is the risk. Wearing it, diluted, is the use.

Lemongrass is a stomach risk when a dog eats the plant, and a research-backed repellent when the oil is properly diluted on the coat. Those two facts get confused constantly, and that confusion is why the internet cannot give you a straight answer on this.

Is lemongrass toxic to dogs?

Yes, according to the ASPCA, and the detail matters more than the headline. The ASPCA Animal Poison Control Center lists lemon grass, Cymbopogon citratus, as toxic to dogs, cats and horses. The toxic principles named are essential oils and cyanogenic glycosides. The clinical signs listed for dogs and cats are stomach upset. For horses the listing is more serious, noting difficulty breathing and weakness.

Read that carefully, because it is a listing about eating the plant. It is not a verdict on a diluted oil applied to a coat, and it is not a reason to dig lemongrass out of your garden. Dogs are not grazers. A dog would need to eat a real quantity of a fibrous grass to run into trouble, and the more common problem with a dog eating any large volume of tough plant material is a physical blockage rather than the plant's chemistry.

So the honest position is this. There is no reason to feed your dog lemongrass, and no benefit that would make it worth doing. If your dog nibbles a stalk in the garden, watch for vomiting or loose stool and call your vet or the ASPCA poison control line on (888) 426-4435 if you are worried.

Which form of lemongrass are we talking about?

Almost every argument online happens because two people are discussing different things. There are four forms a dog might meet, and they carry completely different risks.

The line between rows three and four is the whole conversation. Lemongrass is one of the more skin-irritating essential oils, and the concentration is what separates a deterrent from an irritant. That is not a small distinction you can eyeball at your kitchen counter.

Does lemongrass repel fleas and ticks?

Here's what the research tells us. The active compound doing most of the work is citral, and it has been studied properly.

In laboratory work published in Experimental and Applied Acarology, lemongrass essential oil killed adult ticks, nymphs and larvae of Haemaphysalis longicornis in a dose-dependent way, with mortality above 90 percent at the higher concentrations tested. Microscopy showed physical damage to the ticks, including cracked cuticle and blocked breathing pores. A separate study in Pathogens tested five plant oils against cattle tick and Amblyomma larvae and lemongrass was among the more active of them.

On repellency rather than mortality, work published in BMC Research Notes found lemongrass oil repelled sandflies at very low doses, with full repellency at the concentration tested and strong effect even when the dose was halved. Lemongrass sits in the same plant genus as citronella, which is why the smell is familiar from every mosquito candle you have ever bought.

So the answer is a qualified yes. Lemongrass genuinely interferes with how fleas and ticks find and stay on a host, and the mechanism is established rather than invented by a marketing team.

What lemongrass cannot do

This is the part I want to be unusually blunt about, because if a natural option fails you after what you have already been through, that is not a small disappointment. It sends people back to the thing that hurt their dog.

It does not last. Repellents built on plant essential oils have limited residual activity, generally under two to four hours, because the compounds are volatile and evaporate. That is documented in the repellent literature, and it is the single most important practical fact on this page. A lemongrass spray is a before-the-walk product, not a once-a-month product. Nothing about the chemistry allows it to behave like a monthly dose.

The lab is not a dog. The mortality numbers above come from immersing ticks in oil at concentrations far higher than anything sitting on your dog's coat. Real-world use is about deterrence and reduced attachment, not about the kill rates in those tables.

It does not replace checking your dog. The CDC notes that in most cases a tick must stay attached more than 24 hours before Lyme bacteria can be transmitted, and that removing a tick within 24 hours greatly reduces the chance of infection. Other tick-borne organisms can move faster. No repellent on earth, plant or synthetic, does what your hands do after a walk.

Where lemongrass earns its place

Flea+Tick Lemongrass Repel Spray

The reason to use a formulated spray rather than mixing your own is dilution. Lemongrass has a low ceiling before it irritates skin, and the concentration in a pet formula is set by the people who made it and tested it, not by you counting drops over a sink.

• Lemongrass oil blended with supporting plant oils, diluted for daily use on dogs and cats
• Concentration set by the formulator, so dilution is not left to guesswork
• Applied before walks and reapplied, which is how the chemistry actually works
• Sold as a minimum-risk product under the FIFRA exemption, a regulatory status you can look up yourself

See the Lemongrass Repel Spray

Five lemongrass myths worth clearing up

Myth one: lemongrass is toxic, so a lemongrass spray must be dangerous. The ASPCA listing describes a dog eating the plant. A diluted oil on the coat is a separate question with a separate answer, which is the confusion this whole article exists to sort out.

Myth two: natural means you cannot overdo it. This one worries me most. Lemongrass is among the more skin-irritating essential oils, and the safe topical dilution is lower than for many others. Undiluted oil on a dog is not a minor error. The Merck Veterinary Manual is clear that essential oils can be toxic to animals through skin contact and inhalation, not only when swallowed, and that dogs are at risk too, even though cats are more sensitive.

Myth three: it kills fleas and ticks the way a chemical does. In a dish, at high concentration, lemongrass oil does kill ticks. On your dog, at the concentration in a pet product, you are deterring pests rather than wiping out a population. Both things are useful. They are not the same claim.

Myth four: if it is sold for pets, the EPA reviewed it. Here's what most pet parents are never told. Plant-oil pest products commonly qualify for a minimum-risk exemption under section 25(b) of FIFRA, which means they do not need EPA registration. That exemption was granted because the EPA judged the ingredients low risk, not because efficacy data was reviewed. A Cornell University publication on minimum-risk pesticides spells it out: the exemption means the EPA does not review efficacy data, though labels still may not carry false or misleading claims. Guidance from the Association of American Pesticide Control Officials makes the same point, noting that inclusion on the 25(b) list rested on minimum risk rather than on efficacy or residual action. This cuts both ways, and it is worth knowing in either direction: the exemption is a genuine safety signal about the ingredients, and it is not a performance certificate.

Myth five: lemongrass in the diffuser protects the dog. It does not put anything on your dog where pests land, and diffusing essential oils in a closed room around animals carries its own risks, especially with a cat in the house. Diffusing is for you. Protecting your dog happens on your dog.

Other benefits of lemongrass for dogs

Repelling pests is where the evidence is strongest, but it is not the only place lemongrass shows up in veterinary research.

In a practice laboratory study published in Complementary Medicine Research, 22 essential oils were tested against clinical Malassezia pachydermatis isolates taken from dogs' ears. Lemongrass came out as the most active oil of the group. More recent work in Antibiotics found lemongrass oil among the most effective agents tested against Malassezia biofilms, at a point when the yeast isolates showed reduced susceptibility to conventional antifungal drugs.

That is genuinely interesting, and I want to frame it honestly: these are laboratory findings on isolates in a dish, not a protocol for your dog's ears. If you are dealing with recurring yeast, the answer is not a bottle of lemongrass oil. It starts in the gut, and we've written about that in detail in why yeast in dogs keeps coming back.

What lemongrass is not: a dietary supplement, a dewormer, or anything your dog should swallow. Nothing in the research supports feeding it, and the ASPCA listing is a good reason not to.

Is lemongrass safe around cats?

Cats need their own paragraph, and if you have a cat and a dog sharing a sofa, this applies to you even if the spray is for the dog.

Cats are missing an enzyme, glucuronyl transferase, that most mammals use to process phenolic compounds. The gene for the main version of it, UGT1A6, is a pseudogene in cats, a finding documented across the whole cat family. That is why cats clear compounds like these far more slowly than dogs do. The Merck Veterinary Manual names cats as being at particular risk from essential oils for exactly this reason, and adds that grooming compounds the problem, because a cat licking her coat turns a skin exposure into a swallowed one.

Practically, that means: never apply undiluted oil to a cat, never diffuse in a room a cat cannot leave, read the label of any product before it goes near her, and give a diluted pet spray a patch test on a small area a day ahead even when the label says it is formulated for cats. If she has any liver history at all, ask your vet first.

How to use lemongrass on a dog safely, step by step

1. Use a product formulated for pets. Not an oil from a wellness shop, not a recipe from a forum. You are paying for the dilution work and the testing behind it.
2. Patch test first. One small area, then wait a day. Lemongrass is a known skin sensitiser in sensitive individuals, so this step is not optional.
3. Spray the coat, never the face. Body, legs, belly, under the front legs, around the tail. For the head area, spray into your hands and stroke it on, avoiding eyes, nose and mouth.
4. Apply before you go out, and again as needed. Under two to four hours of residual activity is the working assumption. Before the park, before the trail, before the long grass.
5. Check your dog when you get home. Collar area, eyelids, ears, tail, armpits, between the back legs and between the toes. The CDC advises daily tick checks on dogs, and this is the step that carries the most weight of anything on this list.
6. Handle the house and yard separately. A repellent on the dog does nothing about eggs and larvae in the carpet and bedding.
7. Never give it orally, and store the bottle where neither the dog nor the cat can reach it.

Lemongrass is one layer, and one layer alone leaves gaps. If you want the whole approach, including the household side and what to do when fleas are already on board, we've laid it out in our layered natural flea and tick plan for dogs.

What a reaction to lemongrass looks like

Know the signs before you need them. Watch for drooling, pawing at the face, head shaking, redness or heat at the application site, scratching that starts after you spray rather than before, wobbliness, vomiting, or a dog who goes quiet and flat.

If you see any of it, wash the product off with a mild soap and water rather than waiting to see how it develops, and call your vet or the ASPCA poison control line on (888) 426-4435. Take the bottle with you or photograph the ingredient panel, because the concentration is the first thing anyone will ask about.

DIY lemongrass oil or a formulated spray?

This is the actual decision most pet parents face after reading about lemongrass, so here it is side by side.

One more thing, and it is the reason I wrote this at all. If you are here because something went wrong with a conventional product, you did not do anything wrong. You were handed a routine and not the whole picture. Wanting to know exactly what a plant option does and does not do before you rely on it is not being difficult. That is what informed consent looks like, and it is the same standard you were owed the first time. If that is where you are, what pet parents are not told about flea and tick medication side effects is probably the next thing to read, along with how to support a dog's system after a chemical dose.

Sources

• ASPCA Animal Poison Control Center. Toxic and Non-Toxic Plants: Lemon Grass. aspca.org
• Merck Veterinary Manual. Toxicoses From Essential Oils in Animals. merckvetmanual.com
• Pet Poison Helpline. Essential Oils and Cats. petpoisonhelpline.com
• Court MH et al. Evolution of a Major Drug Metabolizing Enzyme Defect in the Domestic Cat and Other Felidae. PLoS ONE, 2011. PMC3065456
• Effects of the essential oil from Cymbopogon citratus on mortality and morphology of the tick Haemaphysalis longicornis. Experimental and Applied Acarology, 2020. Study record
• Acaricidal Effect of Essential Oils in the Control of Rhipicephalus microplus and Amblyomma mixtum Larvae in Mexico. Pathogens, 2026. Pathogens
• Kimutai A et al. Repellent effects of the essential oils of Cymbopogon citratus and Tagetes minuta on the sandfly, Phlebotomus duboscqi. BMC Research Notes, 2017. PMC5312532
• Better than DEET Repellent Compounds Derived from Coconut Oil. Scientific Reports, 2018. On the limited residual activity of plant essential oil repellents. nature.com
• Bismarck D et al. Antifungal in vitro Activity of Essential Oils against Clinical Isolates of Malassezia pachydermatis from Canine Ears. Complementary Medicine Research, 2014. karger.com
• In Vitro Antifungal Activity of Essential Oils and Nanoemulsions of Zingiber cassumunar and Cymbopogon citratus Against Planktonic and Biofilm Forms of Malassezia pachydermatis. Antibiotics, 2026. PMC13113068
• Association of American Pesticide Control Officials. FIFRA Minimum Risk Pesticides, efficacy data guidance questions and answers, 2021. Published on aapco.org.
• Cornell University. Active Ingredients Eligible for Minimum Risk Pesticide Use. ecommons.cornell.edu
• Centers for Disease Control and Prevention. How Lyme Disease Spreads. cdc.gov
• US Food and Drug Administration. Ticks and Lyme Disease, on daily tick checks for dogs. fda.gov