Is Milfoil Toxic to Dogs and Cats? (2026)

Achillea millefolium

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Mild
Mild
Varies

Quick facts

Toxic to dogsYes
Toxic to catsYes
Toxic to horsesYes
Toxic componentEssential oils and sesquiterpene lactones
Onset of symptomsWithin a few hours
Indoor / outdooroutdoor

If your pet ate this plant

Both lines are staffed 24/7. A consultation fee applies to each. Do not wait for symptoms to appear before calling.

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Symptoms in dogs

  • Vomiting
  • Diarrhea
  • Drooling
  • Skin irritation from contact

Symptoms in cats

  • Vomiting
  • Diarrhea
  • Drooling

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What to do

Usually resolves with monitoring; contact a vet if symptoms are severe or persistent.

Toxic component and mechanism

The toxic component in Milfoil is essential oils and sesquiterpene lactones.

What makes this plant different

Milfoil (Yarrow) causes mild, essential-oil-driven GI upset — its long history as a folk medicine herb doesn't extend to genuine pet safety, though the severity here is mild compared to most other plants on this list.

Plant identification

Scientific name
Achillea millefolium
Family
Asteraceae
Also known as
Milfoil, Yarrow
Typically found
outdoor

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The information on this page is for general informational purposes only and is not a substitute for professional veterinary advice. Plant toxicity data is sourced from the ASPCA Toxic and Non-Toxic Plants database. If you believe your pet has ingested a toxic plant, contact your veterinarian or the ASPCA Animal Poison Control Center (888-426-4435) immediately. Do not wait for symptoms to appear.

Last verified: July 2, 2026 · Cross-referenced with ASPCA Animal Poison Control