Tea tree

Research corpus coverage

Chemistry notes

• CHEMISTRY: Relevant reported constituents include terpinen-4-ol; gamma-terpinene; constituent presence alone does not establish clinical efficacy.

Traditional / historical use

Documented traditional use — not a claim of established efficacy.

• TRADITIONAL: Tea tree has been used for acne; fungal skin conditions; antisepsis; this records historical/traditional use and does not establish efficacy.

  MODERATE · evidence synthesis/fact sheet · NCCIH Herbs at a Glance

Modern evidence

• EVIDENCE: For the major use set (acne; fungal skin conditions; antisepsis), the evidence assessment is limited/mixed: Moderate topical evidence for acne and athlete’s foot symptoms; not established for many other uses.

  MODERATE · regulatory monograph and mixed scientific literature · NCCIH Herbs at a Glance

  Mixed findings, product heterogeneity, or indirect evidence are preserved in the detailed profile.

Forms used traditionally

A listed form does not imply it suits every plant part, or that one preparation is interchangeable with another — see the plant’s own notes below.

Cats

• High risk

  Dermal application of commercial melaleuca (tea tree) oil at inappropriate high doses has been associated with toxicosis in cats.

  Intrinsic toxicity · TOPICAL · commercial essential oil · HIGH · peer_reviewed_veterinary · Toxicity of melaleuca oil and related essential oils applied topically on dogs and cats

• High risk

  Higher-concentration tea tree oil is toxic to cats; topical application or ingestion can cause severe poisoning, and liver failure is described as an example of organ injury.

  Intrinsic toxicity · TOPICAL · concentrated essential oil · HIGH · poison_control_database · Tea Tree Oil Is Toxic To Dogs

• High risk

  Tea tree oil is known to cause poisoning in cats and may produce neurologic, respiratory, cardiovascular, thermoregulatory, gastrointestinal, and hepatic signs.

  Intrinsic toxicity · OTHER · tea tree essential oil · HIGH · poison_control_database · Essential Oils and Cats

Dogs

• High risk

  Dermal application of commercial melaleuca (tea tree) oil at inappropriate high doses has been associated with toxicosis in dogs.

  Intrinsic toxicity · TOPICAL · commercial essential oil · HIGH · peer_reviewed_veterinary · Toxicity of melaleuca oil and related essential oils applied topically on dogs and cats

• High risk

  Tea tree oil (melaleuca) is listed as poisonous to dogs; certain concentrated oils can affect the nervous system, with tea tree oil given as an example.

  Intrinsic toxicity · OTHER · Tea tree essential oil · HIGH · veterinary_hospital_guidance · Essential Oil and Liquid Potpourri Poisoning in Dogs

• High risk

  Higher-concentration tea tree oil is toxic to dogs; topical application or ingestion of even a few concentrated drops can cause severe poisoning.

  Intrinsic toxicity · TOPICAL · concentrated essential oil · HIGH · poison_control_database · Tea Tree Oil Is Toxic To Dogs

• High risk

  Concentrated tea-tree oil can cause toxicosis in dogs after dermal or oral exposure; the page describes it as a common essential-oil offender in dogs.

  Intrinsic toxicity · OTHER · Concentrated essential oil · HIGH · poison_control_database · Essential Oils Are Toxic to Dogs | Pet Poison Helpline®

• Caution

  The low concentrations of tea-tree oil in various dog shampoos are not identified by the page as the cause of reported toxicities; concentrated products are described as the primary culprit.

  Intrinsic toxicity · TOPICAL · Low-concentration dog shampoo · HIGH · poison_control_database · Essential Oils Are Toxic to Dogs | Pet Poison Helpline®

Cats & dogs

• Contraindicated

  100% tea tree (melaleuca) oil should never be used on cats or dogs; dermal exposure can cause severe intoxication and may be fatal.

  Intrinsic toxicity · TOPICAL · 100% essential oil · HIGH · poison_control_database · Tea Tree Oil - American College of Veterinary Pharmacists

• High risk

  Melaleuca (tea-tree) oil is listed among essential oils associated with products that can be toxic in dogs and/or cats; the page does not provide oil-specific species, route, dose, or sign attribution.

  Intrinsic toxicity · OTHER · Essential oil, including as a component of herbal flea or tick treatments · MODERATE · veterinary_manual · essential, herbal, oil poisoning canine feline - Consultant

• High risk

  Veterinary poison-control cases document depression, weakness, incoordination, and tremors after dermal application of melaleuca oil to dogs and cats; most cases involved inappropriately high topical exposure.

  Intrinsic toxicity · TOPICAL · essential oil · HIGH · veterinary_case_series · Toxicity of melaleuca oil and related essential oils applied topically on dogs and cats

• High risk

  Tea tree (melaleuca) oil is included among essential oils described as toxic to dogs and cats; exposure may produce the general essential-oil effects reported by the page.

  Intrinsic toxicity · OTHER · tea-tree essential oil or liquid-potpourri product · MODERATE · veterinary_hospital_guidance · Steer clear of essential oils - VCA Animal Hospitals

• High risk

  Tea tree oil intoxication in cats and dogs may produce hypothermia, weakness, ataxia, tremors, bradycardia, and skin irritation; signs may begin within 1–2 hours but can be delayed up to 8 hours after application.

  Intrinsic toxicity · TOPICAL · tea tree essential oil · HIGH · poison_control_database · Tea Tree Oil - American College of Veterinary Pharmacists

• High risk

  Tea-tree oil is a commonly reported essential-oil intoxicant in pets; concentrated tea-tree oil toxicosis has been reported in dogs and cats, and tea-tree oil is identified as potentially hepatotoxic.

  Intrinsic toxicity · OTHER · concentrated tea-tree essential oil and tea-tree-containing products · HIGH · veterinary_manual · Toxicosis por aceites esenciales en animales - Toxicología

• High risk

  Tea tree oil has documented evidence of causing fatalities in small animals when applied to fur or skin, with possible oral ingestion or transdermal absorption.

  Intrinsic toxicity · OTHER · essential oil · HIGH · veterinary_manual · Herbal Medicine in Veterinary Patients - Therapeutics

• High risk

  Concentrated tea tree oil toxicosis has been reported in dogs and cats, and tea tree oil is listed as potentially hepatotoxic.

  Intrinsic toxicity · INHALATION · concentrated tea tree essential oil · HIGH · veterinary_manual · Toxicoses From Essential Oils in Animals - Toxicology

• High risk

  Tea tree oil, also called melaleuca oil, is listed as an essential oil known to cause poisoning in dogs and cats after oral or dermal exposure.

  Intrinsic toxicity · OTHER · essential oil · HIGH · poison_control_database · Updates on Essential Oils

• High risk

  Tea-tree (melaleuca) essential oil is listed among common essential oils that can cause poisoning in animals.

  Intrinsic toxicity · OTHER · essential oil · HIGH · poison_control_database · Essential Oils | Pet Poison Helpline®

• High risk

  Tea tree oil (melaleuca oil) is highly toxic to dogs and cats, especially cats, after oral or topical exposure.

  Intrinsic toxicity · OTHER · Tea tree oil; topical antibacterial preparation · HIGH · veterinary_hospital_guidance · Small Animal Toxins | Cornell University College of Veterinary ...

• Caution

  Melaleuca (tea-tree) oil has been associated with ataxia, incoordination, weakness, tremors, and depression in animals.

  Intrinsic toxicity · UNKNOWN · Essential oil · MODERATE · peer_reviewed_veterinary · Toxicity of Insecticides and Skin Care Products of Botanical Origin

• Caution

  Appropriately diluted tea tree oil products may be used only with veterinary guidance; the page emphasizes consultation with a veterinarian before use.

  Intrinsic toxicity · TOPICAL · appropriately diluted tea tree oil products · HIGH · poison_control_database · Tea Tree Oil - American College of Veterinary Pharmacists

• Caution

  Concentrated tea tree (melaleuca) oil may cause problems in pets, with effects varying according to the oil and formulation; the page notes that only a small number of drops may cause problems for some oils.

  Intrinsic toxicity · OTHER · concentrated tea tree oil · MODERATE · poison_control_database · The Essentials of Essential Oils Around Pets

• Low concern

  Low-concentration tea tree oil products, including some shampoos and body washes, are generally not considered toxic to cats and dogs.

  Intrinsic toxicity · UNKNOWN · low-concentration shampoos and body washes · MODERATE · poison_control_database · Tea Tree Oil - American College of Veterinary Pharmacists

• Low concern

  Low-concentration tea tree oil pet products, including shampoos, are generally considered non-toxic when used according to labeled directions.

  Intrinsic toxicity · TOPICAL · low-concentration pet product; shampoo · HIGH · poison_control_database · Tea Tree Oil Is Toxic To Dogs

Additional safety notes (general, unstructured)

Free-text safety notes carried from their source — not broken out by species, route, or hazard type, and not equivalent to the structured records above. Each note names the kind of source it came from.

• SAFETY: Major issues include Toxic if swallowed; contact dermatitis; oxidation increases sensitization. Contraindications/cautions include Oral use; application near infants.

  HIGH · observational/case series and expert review · LiverTox: Herbal and Dietary Supplements

• SAFETY: Clinically relevant interaction concerns include No major systemic interactions established for topical use.

  MODERATE · observational/case series and expert review · LiverTox: Herbal and Dietary Supplements

  Some interactions are theoretical or based on case reports/pharmacokinetics rather than outcome trials.

• SAFETY: Pregnancy/lactation reference: Avoid oral use; topical pregnancy/lactation data limited.

  MODERATE · regulatory monograph or evidence synthesis · NCCIH Herbs at a Glance

  Absence of evidence is not evidence of safety.

• Melaleuca (tea-tree) oil is listed among essential oils associated with products that can be toxic in dogs and/or cats; the page does not provide oil-specific species, route, dose, or sign attribution.

  MODERATE · veterinary_manual · essential, herbal, oil poisoning canine feline - Consultant

  The page names tea-tree oil but does not attribute the listed signs specifically to it or distinguish cats from dogs.

• Melaleuca (tea-tree) oil has been associated with ataxia, incoordination, weakness, tremors, and depression in animals.

  MODERATE · peer_reviewed_veterinary · Toxicity of Insecticides and Skin Care Products of Botanical Origin

  The page does not specify species, route, dose, concentration, or preparation details beyond identifying Melaleuca oil.

• Veterinary poison-control cases document depression, weakness, incoordination, and tremors after dermal application of melaleuca oil to dogs and cats; most cases involved inappropriately high topical exposure.

  HIGH · veterinary_case_series · Toxicity of melaleuca oil and related essential oils applied topically on dogs and cats

  This is specific evidence for topical concentrated melaleuca oil; it does not prove equal risk for tea-tree leaf, infusion, or infused oil.

• Tea tree (melaleuca) oil is included among essential oils described as toxic to dogs and cats; exposure may produce the general essential-oil effects reported by the page.

  MODERATE · veterinary_hospital_guidance · Steer clear of essential oils - VCA Animal Hospitals

  The page names tea tree oil but does not provide tea-tree-specific constituent, dose, or clinical-sign data.

• 100% tea tree (melaleuca) oil should never be used on cats or dogs; dermal exposure can cause severe intoxication and may be fatal.

  HIGH · poison_control_database · Tea Tree Oil - American College of Veterinary Pharmacists

  The page does not name a specific toxic constituent.

• Appropriately diluted tea tree oil products may be used only with veterinary guidance; the page emphasizes consultation with a veterinarian before use.

  HIGH · poison_control_database · Tea Tree Oil - American College of Veterinary Pharmacists

  The page does not specify a safe concentration or provide separate cat and dog guidance.

• Low-concentration tea tree oil products, including some shampoos and body washes, are generally not considered toxic to cats and dogs.

  MODERATE · poison_control_database · Tea Tree Oil - American College of Veterinary Pharmacists

  The page does not define the concentrations considered low and does not separately distinguish cats from dogs.

• Tea tree oil intoxication in cats and dogs may produce hypothermia, weakness, ataxia, tremors, bradycardia, and skin irritation; signs may begin within 1–2 hours but can be delayed up to 8 hours after application.

  HIGH · poison_control_database · Tea Tree Oil - American College of Veterinary Pharmacists

  Signs are reported for cats and dogs together, without species-specific differentiation.

• Concentrated tea tree (melaleuca) oil may cause problems in pets, with effects varying according to the oil and formulation; the page notes that only a small number of drops may cause problems for some oils.

  MODERATE · poison_control_database · The Essentials of Essential Oils Around Pets

  The example is not assigned separately to cats versus dogs, no clinical signs are specified, and no toxic constituent is named.

• Tea-tree oil is a commonly reported essential-oil intoxicant in pets; concentrated tea-tree oil toxicosis has been reported in dogs and cats, and tea-tree oil is identified as potentially hepatotoxic.

  HIGH · veterinary_manual · Toxicosis por aceites esenciales en animales - Toxicología

  The page does not identify a specific toxic constituent for tea-tree oil.

• Tea tree oil has documented evidence of causing fatalities in small animals when applied to fur or skin, with possible oral ingestion or transdermal absorption.

  HIGH · veterinary_manual · Herbal Medicine in Veterinary Patients - Therapeutics

  The page states small animals but does not specify individual species.

• Concentrated tea tree oil toxicosis has been reported in dogs and cats, and tea tree oil is listed as potentially hepatotoxic.

  HIGH · veterinary_manual · Toxicoses From Essential Oils in Animals - Toxicology

  The page provides no tea-tree-specific route, concentration, dose, or case-level clinical details.

• Low-concentration tea tree oil pet products, including shampoos, are generally considered non-toxic when used according to labeled directions.

  HIGH · poison_control_database · Tea Tree Oil Is Toxic To Dogs

  The page does not identify a toxic constituent and does not provide species-specific safety details for each product.

• Tea tree oil, also called melaleuca oil, is listed as an essential oil known to cause poisoning in dogs and cats after oral or dermal exposure.

  HIGH · poison_control_database · Updates on Essential Oils

  The page does not name a tea-tree-oil toxic constituent.

• Tea-tree (melaleuca) essential oil is listed among common essential oils that can cause poisoning in animals.

  HIGH · poison_control_database · Essential Oils | Pet Poison Helpline®

  No tea-tree-specific toxic constituent, dose, route-specific profile, or sign profile is provided.

• Tea tree oil (melaleuca oil) is highly toxic to dogs and cats, especially cats, after oral or topical exposure.

  HIGH · veterinary_hospital_guidance · Small Animal Toxins | Cornell University College of Veterinary ...

  The page names melaleuca oil but does not identify a separate toxic constituent or provide concentration distinctions.

• Dermal application of commercial melaleuca (tea tree) oil at inappropriate high doses has been associated with toxicosis in cats.

  HIGH · peer_reviewed_veterinary · Toxicity of melaleuca oil and related essential oils applied topically on dogs and cats

  The page does not provide numerical doses or concentrations; reported cases recovered with treatment and supportive care within 2–3 days.

• Higher-concentration tea tree oil is toxic to cats; topical application or ingestion can cause severe poisoning, and liver failure is described as an example of organ injury.

  HIGH · poison_control_database · Tea Tree Oil Is Toxic To Dogs

  The page states that higher concentrations are toxic to pets and gives liver failure specifically as an example in a cat; the remaining clinical signs are not separately labeled as cat-specific.

• Tea tree oil is known to cause poisoning in cats and may produce neurologic, respiratory, cardiovascular, thermoregulatory, gastrointestinal, and hepatic signs.

  HIGH · poison_control_database · Essential Oils and Cats

  The page names tea tree oil but does not identify its toxic constituent or distinguish route.

• Dermal application of commercial melaleuca (tea tree) oil at inappropriate high doses has been associated with toxicosis in dogs.

  HIGH · peer_reviewed_veterinary · Toxicity of melaleuca oil and related essential oils applied topically on dogs and cats

  The page does not provide numerical doses or concentrations; reported cases recovered with treatment and supportive care within 2–3 days.

• Tea tree oil (melaleuca) is listed as poisonous to dogs; certain concentrated oils can affect the nervous system, with tea tree oil given as an example.

  HIGH · veterinary_hospital_guidance · Essential Oil and Liquid Potpourri Poisoning in Dogs

  The page does not name a specific toxic constituent or provide tea-tree-specific route or dose information.

• Higher-concentration tea tree oil is toxic to dogs; topical application or ingestion of even a few concentrated drops can cause severe poisoning.

  HIGH · poison_control_database · Tea Tree Oil Is Toxic To Dogs

  The page title specifically identifies toxicity in dogs, while the clinical-sign list is presented generally for pets rather than as dog-specific findings.

• Concentrated tea-tree oil can cause toxicosis in dogs after dermal or oral exposure; the page describes it as a common essential-oil offender in dogs.

  HIGH · poison_control_database · Essential Oils Are Toxic to Dogs | Pet Poison Helpline®

  The page does not name a toxic constituent.

• The low concentrations of tea-tree oil in various dog shampoos are not identified by the page as the cause of reported toxicities; concentrated products are described as the primary culprit.

  HIGH · poison_control_database · Essential Oils Are Toxic to Dogs | Pet Poison Helpline®

  The page does not explicitly label low-concentration dog shampoos as non-toxic.

Taxonomic identity note

• Tea tree is treated here as Melaleuca alternifolia (Maiden & Betche) Cheel in the family Myrtaceae; recorded older names include Melaleuca linariifolia var. alternifolia Maiden & Betche.