Oregano
Also known as Greek Oregano. One plant, one grade per pet — the verdicts below are transcribed from primary sources and human-reviewed.
Oregano is mildly toxic to cats (S1 Caution): the ASPCA lists gastrointestinal irritants causing mild vomiting and diarrhea — an upset stomach, not a poisoning.
FULL VERDICT →Oregano is mildly toxic to dogs (S1 Caution): the ASPCA lists gastrointestinal irritants causing mild vomiting and diarrhea.
FULL VERDICT →Care at a glance
What happens if it's eaten
Signs on record for each animal, transcribed from the cited sources.
- vomiting (mild)
- diarrhea (mild)
- vomiting (mild)
- diarrhea (mild)
When to call the vet
Call your vet if vomiting or diarrhea persists or worsens, or your cat stops eating or drinking.
FULL VERDICT →Call your vet if vomiting or diarrhea persists or worsens, or your dog stops eating or drinking.
FULL VERDICT →FAQ
Is oregano oil covered by this verdict?
No — our record covers the plant, and the sources say nothing about the oil. The ASPCA's oregano entry is for Origanum vulgare hirtum, the growing herb, with "Gastrointestinal irritants" and "Mild vomiting and diarrhea" as its whole record; it does not mention essential oil, and Pet Poison Helpline has no oregano entry at all. We do not extend a plant grade to a concentrated extract, so the S1 Caution here applies to leaves and stems only. If a pet has swallowed oregano oil, that is a question for your vet or a poison hotline, not for this page.
Which herbs on the same windowsill are safe, and which are not?
On our records, most are safe and oregano is one of the exceptions. The ASPCA lists basil, rosemary, thyme, sage, cilantro, and lemon balm as non-toxic — all S0 Safe. Oregano is S1 Caution on "Mild vomiting and diarrhea," and garden mint is S1 too, with vomiting and diarrhea after large ingestions. Parsley is S2 Irritant for a skin reaction after large amounts. None of these is a poisoning; the S1 and S2 herbs are the ones to keep out of grazing reach. Every grade above links to its record.