Study summary
Toxicoses from essential oils in animals
Read the original paper- Study type
- Review
- Species tested
- Dogs, cats, birds
- Published in
- Merck Veterinary Manual
How it was tested
An authoritative clinical reference article, not a primary study.
Summary
The Merck Veterinary Manual's reference on essential-oil poisoning in animals, explaining how pets are exposed (skin contact, grooming, inhalation) and why cats are the most vulnerable species.
Key findings
Cats are deficient in the enzyme glucuronyl transferase, which leaves them highly sensitive to the phenols in some oils. The manual names cinnamon, cassia, pennyroyal, tea tree, and birch tar among potentially liver-damaging oils, and cedar, eucalyptus, wintergreen, pennyroyal, sage, and wormwood among those that can trigger seizures; wintergreen and birch can also cause aspirin-type toxicity from their methyl salicylate. Reported signs run from drooling, vomiting, and lethargy to tremors, low body temperature, and seizures.
Limitations
A tertiary clinical reference reflecting consensus, not original dose-response data or case counts.