Is Citronella Toxic to Dogs? | A Pet Safety Warning Guide

Introduction: Separating Myth from Medical Fact

You are standing in the garden center, holding a pot of lemon-scented grass, asking yourself: is citronella toxic to dogs? It is the most common question I hear from pet owners fighting the summer mosquito invasion. We want a bug-free yard, but we don’t want to hurt our four-legged digging companions.

The answer isn’t a simple yes or no. It depends entirely on what form of citronella you are using.

The Direct Answer: Citronella plants (Cymbopogon nardus) are mildly toxic to dogs. If your dog chews on the grass, they will likely suffer from gastrointestinal upset like vomiting or diarrhea. However, concentrated citronella essential oils are dangerous. They pose a high risk of central nervous system depression, muscle weakness, and liver damage.

We need to break this down by plant, product, and chemistry so you can keep your garden safe.

Understanding Citronella: Distinguishing True Grass from the ‘Mosquito Plant’

As a gardener, I see people mix these up constantly. Not all plants sold as “citronella” are the same species. They have different chemical profiles, which means they impact your dog differently.

Cymbopogon nardus (True Citronella Grass)

This is the source of the oil. It is a coarse, clumping grass that can grow up to 6 feet tall in the right zones.

• The Risk: Mild.
• The Scenario: Your dog eats the long, grassy blades.
• The Result: The plant matter is tough and fibrous. The combination of physical irritation in the stomach and the essential oils in the leaves usually leads to puking up the grass or loose stool.

Pelargonium citrosum (Citronella Geranium / Mosquito Plant)

Marketing teams love this plant. It smells like lemon, but it is actually a scented geranium. It does not contain the same oil density as the grass and is largely ineffective against mosquitoes despite the label.

• The Risk: Mild to Moderate.
• The Scenario: Your dog chews the crinkly, lobed leaves.
• The Result: Geraniums contain geraniol and linalool. These compounds irritate the skin and mucous membranes. If a dog eats enough, you will see more than just an upset stomach; you might see skin rashes around the mouth.

The Spectrum of Risk: Concentration is Everything

The dose makes the poison. A dog walking past a plant is fine. A dog chewing a leaf is uncomfortable. A dog licking a spilled bottle of essential oil is in trouble.

1. Raw Plant Material

When a dog eats the plant, they are getting a diluted dose of the oil mixed with a lot of fiber.

• Severity: Low.
• Metric: Most dogs stop eating it after the first taste because it is bitter.

2. Citronella Candles and Waxes

These products contain citronella oil suspended in paraffin or soy wax.

• Severity: Moderate.
• The Real Danger: While the oil causes stomach cramps, the wax is the bigger issue. If a Labrador eats a whole candle (and they will), you are looking at a bowel obstruction from the wax ball, not just chemical toxicity.

3. Concentrated Essential Oils

This is where is citronella toxic to dogs becomes a serious medical conversation. Essential oils are volatile organic compounds distilled down to high potency.

• Severity: High / Emergency.
• Absorption: Oils absorb rapidly through the skin or gums. They don’t need to be swallowed to do damage.
• The Damage: If applied to the skin or ingested, these concentrates attack the nervous system and the liver.

Data Table: Citronella Toxicity – Plant vs. Products

Citronella Form	Primary Toxic Compounds	Likely Symptoms	Severity	Action Required
Plant (Leaves/Stems)	Citronellal, Geraniol	Vomiting, Diarrhea, Drooling	Mild	Monitor at home. Call vet if vomiting persists > 24 hrs.
Essential Oil (Undiluted)	Concentrated Citronellal	Tremors, Weakness, Skin Burns, Liver Failure	High	IMMEDIATE Vet Visit. Do not wait.
Candles/Wax	Oils + Paraffin	Constipation (blockage), Vomiting	Moderate	Call vet to assess obstruction risk.
Diffusers (Vapor)	Airborne Particles	Coughing, Sneezing, Lethargy	Mild/Mod	Move dog to fresh air immediately.

The Science: Why Dogs Can’t Handle Citronella

We need to look at the biology. Humans process these plant compounds easily. Dogs do not.

The main compounds in citronella are citronellal, geraniol, and citronellol. These are terpenes. To get rid of these compounds, the liver needs to attach a sugar molecule to them to make them water-soluble so they can be peed out. This process is called glucuronidation.

Dogs have a deficiency in the enzymes needed for this process compared to humans. Because they cannot break the chemicals down fast enough, the toxins build up in the blood. This accumulation leads to liver damage and central nervous system (CNS) shock.

Recognizing the Signs: Symptoms of Poisoning

You know your dog better than anyone. If they are acting “off,” pay attention. Symptoms of citronella poisoning usually show up within 30 minutes to 2 hours after exposure.

The “Wait and See” Symptoms (Mild Exposure)

• Hypersalivation: Excessive drooling.
• Emesis: Vomiting, usually smelling of lemon.
• Diarrhea: Loose or watery stool.
• Pawing at the mouth: This indicates the oils are burning their gums.

The “Go to the Vet Now” Symptoms (Severe Exposure)

• Ataxia: This is the technical term for walking like they are drunk. Stumbling, falling over, or looking dizzy.
• Muscle Tremors: Shaking or shivering that isn’t cold-related.
• Respiratory Distress: Panting heavily, coughing, or wheezing (often caused by inhaling droplets from a diffuser).
• Lethargy: The dog won’t get up, won’t play, and seems unresponsive.
• Skin Redness: If the oil touched their skin, look for bright red, inflamed patches (contact dermatitis).

Emergency Response Guide

If you suspect your dog has ingested a significant amount of citronella, or any essential oil, follow this protocol.

1. Remove the Source

Get the dog away from the plant or product. If it is an oil spill, put the dog in another room or outside immediately.

2. Check the Skin

If the oil is on their fur or skin, do not just rinse it with water. Oils are hydrophobic; water pushes them deeper into the skin.

• Action: Use mild dish soap (like Dawn) which cuts grease. Wash the area thoroughly with warm water to strip the oil from the coat.

3. Do NOT Induce Vomiting

This is critical. If your dog swallowed essential oils, making them vomit can cause them to inhale the oil into their lungs. This causes aspiration pneumonia, which kills faster than the toxicity itself. Only induce vomiting if a veterinarian explicitly tells you to.

4. Make the Call

Have these numbers saved in your phone:

• Your Local Vet
• ASPCA Animal Poison Control: (888) 426-4435
• Pet Poison Helpline: (855) 764-7661

Have this info ready:

• Weight of the dog.
• Time of ingestion.
• Product name (or plant type).
• Estimated amount eaten.

Pro-Tips for a Pet-Safe Garden

You can still have a bug-free garden without risking your dog’s health. Here is how I manage it in my own backyard.

1. Vertical Gardening

I grow my “risky” herbs in elevated planters. A trough planter that stands 30 inches off the ground keeps Pelargonium citrosum out of reach for terriers and beagles. For larger breeds, use hanging baskets.

2. The Physical Barrier

If you plant citronella grass in the ground, place it behind a decorative fence or in the back border of a deep flower bed. Use dense, non-toxic shrubs like Boxwood or Rosemary in front of it to act as a “green wall” that stops the dog from getting to the citronella.

3. Pet-Safe Alternatives

Forget the citronella. There are plants that repel bugs and are safer for dogs.

• Rosemary (Rosmarinus officinalis): Generally safe and hardy. The woody scent confuses mosquitoes.
• Catnip (Nepeta cataria): Research suggests catnip oil is actually more effective at repelling mosquitoes than citronella. It makes cats act crazy, but for dogs, it’s generally safe (though it acts as a mild sedative).
• Basil (Ocimum basilicum): Great for cooking, safe for dogs, and flies hate it.

4. Ditch the Diffuser

If you have a dog, using an essential oil diffuser is rarely worth the risk. Their sense of smell is thousands of times stronger than ours. What smells “fresh” to you smells like a chemical factory to them. If you must use one, keep it in a room the dog cannot access.

Final Thoughts on Garden Safety

When we ask is citronella toxic to dogs, we are really asking about risk management. The plant in the corner of the yard is a low risk. The bottle of oil on the coffee table is a high risk.

My advice? stick to safe alternatives like Rosemary and Basil near the patio, and keep the chemical warfare products locked in the shed. Your dog relies on you to check the labels. Keep their paws safe, and happy gardening.

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Frequently Asked Questions

Can dogs be around citronella candles?

Ideally, no. While the smoke is less toxic than the oil, it can irritate a dog’s sensitive respiratory system. If you use them, ensure the area is well-ventilated and the candle is placed high up where the dog cannot knock it over or eat the wax.

How much citronella will kill a dog?

There is no single “lethal dose” metric because it depends on the dog’s size and the concentration of the product. However, small dogs can suffer severe poisoning from ingesting just a few milliliters of pure essential oil. Any ingestion of pure oil is a medical emergency.

Is the “Mosquito Plant” safe for dogs?

No, the “Mosquito Plant” (Pelargonium citrosum) is toxic. While it is different from citronella grass, it contains geraniol and linalool, which cause vomiting and skin irritation. It is not a safe alternative for a dog-friendly garden.

What happens if a dog licks citronella spray?

If the spray is a pet-safe formula, they might just drool due to the bad taste. If it is a bug spray meant for furniture or humans, it likely contains high concentrations of oils or other chemicals. Wash their mouth out and contact your vet immediately.

Are there any dog-safe mosquito repellents?

Yes. Look for products specifically labeled for use on dogs. These often use cedarwood oil or very diluted mixtures of peppermint/clove oil that are formulated to be safe. Never apply human insect repellent (DEET) to a dog; it is highly toxic.