Marjoram Toxic?

Updated 2026-03-06| 5 min read| 2,487 found this helpful

Marjoram is confirmed toxic to cats and dogs, while its toxicity to horses remains unstudied and unknown.

Its core toxic principles are unspecified gastrointestinal irritants that trigger digestive distress in affected animals.

No formal animal poisoning cases are recorded in literature, but the plant is explicitly not appropriate for animal feed use.

FAQ

Is Marjoram toxic to Humans?

No confirmed toxicity under standard culinary use; mild digestive upset may only occur with extremely large, excessive ingestion. (Non-toxic)

Is Marjoram toxic to Cats?

Vomiting, diarrhea, mild abdominal discomfort (Low)

Is Marjoram toxic to Dogs?

Vomiting, diarrhea, mild abdominal discomfort (Low)

Is Marjoram toxic to Horses?

No clinical signs confirmed, as toxicity to horses has not been formally evaluated. (Unknown)

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Toxicity Details

Humans

Non-toxic

No confirmed toxicity under standard culinary use; mild digestive upset may only occur with extremely large, excessive ingestion.

Cats

Low

Vomiting, diarrhea, mild abdominal discomfort

Dogs

Low

Vomiting, diarrhea, mild abdominal discomfort

Horses

Unknown

No clinical signs confirmed, as toxicity to horses has not been formally evaluated.

Toxicity Snapshot

Toxic PartsNo animal poisoning cases have been described in published literature to date; the entire plant is unsuitable for animal feed.

Exposure RouteIngestion of plant material (leaves, stems, flowers) is the primary confirmed exposure route.

Toxic CompoundsUnspecified gastrointestinal irritants (per ASPCA)

First Aid & Prevention

First 30 Minutes

• Remove all remaining marjoram plant material from the animal's mouth and immediate environment right away.
• Do not induce vomiting unless explicitly instructed to do so by a licensed veterinarian.
• Offer small sips of fresh water to soothe irritation if the animal is alert, responsive, and able to swallow normally.

Contact Vet Immediately

• If your cat or dog has ingested marjoram and develops vomiting, diarrhea, or lethargy after exposure.
• If digestive symptoms persist for more than 2 hours after ingestion, or if the animal refuses food or water.
• If a horse has ingested large quantities of marjoram and exhibits any unusual behavioral or physical changes.

Prevention

• Keep potted or cut marjoram plants out of reach of cats, dogs, and other companion animals at all times.
• Never add marjoram or marjoram-derived products to homemade animal feed, treats, or forage supplies.
• Label garden-planted marjoram clearly to avoid accidental harvesting for animal consumption.

Treatment & Prognosis

• Veterinary supportive care including fluid therapy to correct dehydration from prolonged vomiting or diarrhea.
• Vet-prescribed anti-emetic or antidiarrheal medications to manage symptomatic digestive distress as needed.
• Electrolyte level monitoring for animals with severe, prolonged digestive symptoms to prevent complications.

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Professional Toxicology

Scientific NameOriganum majorana

AliasesKnotted Marjoram、Pot Marjoram

Toxicity Grade

HumansNon-toxic

CatsLow

DogsLow

HorsesUnknown

Target Organs

Gastrointestinal tract (stomach, small and large intestines)

Mechanism of Action

• Unspecified gastrointestinal irritants inflame the lining of the stomach and intestines, triggering protective vomiting and diarrhea responses in susceptible species.

Other Species Risk (CliniTox)

Information from CliniTox veterinary text.

Small companion mammals (rabbits, guinea pigs, hamsters): No formal toxicity data is available, but ingestion is not recommended as it may trigger mild digestive upset.

Ruminants (cattle, sheep, goats): No confirmed poisoning cases have been documented, but marjoram is not considered suitable for use as regular forage.

Confusion Risk

The following plants look similar and may be confused:

Other Origanum species (e.g. common oregano) Origanum spp.

Closely related species in the Origanum genus are highly visually and aromatically similar to marjoram, and may carry equivalent low toxicity risks for companion animals.

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Related Toxic Plants

Perilla mint

Perilla frutescens

High toxicity for cattle, horses, and ruminants; can cause fatal acute respiratory distress syndrome even with small ingestion.

Ground ivy

Glechoma hederacea

Moderate toxicity for cats, dogs, and horses; causes digestive upset, liver damage, and respiratory issues in large doses.

Common sage (excessive doses)

Salvia officinalis

Low to moderate toxicity for cats and dogs; can trigger seizures, vomiting, and tachycardia if ingested in large quantities.

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Data Sources

1. ASPCA Animal Poison Control

2. CliniTox (Universität Zürich)

This information is for reference only and does not constitute medical advice. If ingestion or poisoning is suspected, seek medical or veterinary attention immediately.