Is Yarrow Toxic to Cats and Dogs?
Yarrow is a common garden perennial that is toxic to cats, dogs, and horses. Also known as milfoil, this plant contains compounds that can cause a range of symptoms if a pet chews on or eats it. While yarrow is valued by many gardeners, pet owners should understand the risks it poses to their animals.
Yarrow belongs to the Asteraceae family. Its toxicity applies to dogs, cats, and horses, so caution is necessary for households with these pets.
Yarrow: what the ASPCA database lists
| ASPCA entry | Yarrow |
|---|---|
| Other common names | Milfoil, Soilder’s Woundwort, Dog Daisy Thousand Seal, Devil’s Nettle, Old Man’s Pepper |
| Scientific name | Achillea millefolium |
| Family | Asteraceae |
| Toxic to | Toxic to Dogs, Toxic to Cats, Toxic to Horses |
| Non-toxic to | None listed |
| Toxic principles | glycoalkaloids (achillein), monoterpenes, sesquiterpene lactones (achillin) |
| Clinical signs listed | Vomiting, diarrhea, colic, drooling, anorexia, dermatitis, depression |
What the ASPCA lists for yarrow
The American Society for the Prevention of Cruelty to Animals (ASPCA) lists yarrow, or Achillea millefolium, as toxic to cats, dogs, and horses. The plant contains several toxic principles, including glycoalkaloids like achillein, monoterpenes, and sesquiterpene lactones like achillin. These chemical compounds are found throughout the plant and are responsible for the adverse reactions seen in pets.
According to the ASPCA, ingestion can lead to a variety of clinical signs. Pet owners might observe:
- Vomiting
- Diarrhea
- Colic
- Drooling
- Loss of appetite (anorexia)
- Depression
- Skin irritation (dermatitis)
These symptoms are the body’s reaction to the plant’s toxic components. The severity of the signs often depends on how much of the plant the animal consumed. Skin irritation, or dermatitis, can occur from direct contact with the plant.
What this means in a home with pets
Having yarrow in a home or garden requires careful management if pets are present. Cats and dogs that chew on plants out of boredom, curiosity, or habit could ingest enough to become ill. Even a small amount can cause gastrointestinal upset like vomiting or diarrhea. While many animals may be deterred by the plant’s scent or taste, this is not a reliable safety measure.
Puppies and kittens are often more likely to explore new things with their mouths, putting them at a higher risk of accidental poisoning. Supervision is necessary for young or inquisitive pets around any potentially toxic plants. The plant is also known by several other common names, including milfoil, soldier’s woundwort, dog daisy, thousand seal, devil’s nettle, and old man’s pepper. Knowing these names helps pet owners identify yarrow in different settings, such as in wildflower mixes or on walks.
Keeping cats and dogs and this plant apart
The most effective way to prevent yarrow poisoning is to ensure pets cannot access the plant. For outdoor gardens, consider using pet-safe fencing or planting yarrow in an area that is completely inaccessible to your dog. If you have an indoor cat that goes outside on a leash or in a catio, make sure the yarrow is planted well out of their reach.
For indoor arrangements, avoid using fresh or dried yarrow in bouquets. If yarrow is already present in your home or yard, consistent supervision is key. Redirect your pet’s attention with a toy or a treat if you see them showing interest in the plant. Always read the labels on any new plants you bring home to confirm they are safe for pets.
When to call your vet
If your pet chewed or ate part of this plant, call your veterinarian or an animal poison control line. Note which plant and which part, how much may be gone and when, and take a photo or a piece of the plant with you.
If you suspect your pet has eaten any part of a yarrow plant, contact your veterinarian or the ASPCA Animal Poison Control Center immediately. Be prepared to share what part of the plant was eaten, how much, and when the ingestion occurred. Do not attempt to induce vomiting or provide any home remedies without professional veterinary guidance.
Emergency signs: go now
- Collapse, fainting or severe weakness
- Seizures, tremors or trouble standing
- Trouble breathing or blue, gray or very pale gums
- Repeated vomiting or retching, or a swollen, painful belly
- Any known contact with a substance listed as toxic, even before signs appear
Book an appointment soon
- Vomiting or diarrhea that lasts or keeps coming back
- Not eating or drinking, or drinking much more than usual
- Drooling, pawing at the mouth or a swollen face
- Lethargy, hiding or acting unlike themselves
ASPCA Animal Poison Control Center: (888) 426-4435 (a consultation fee may apply). Your own vet or nearest emergency clinic is always a good first call.
Sources
Last checked October 21, 2026. Listings and guidance can change; your veterinarian knows your pet’s health history.