Leek

Dangerous

Verdict

Never — allium family, highly toxic to cats.

Toxic principle: thiosulfate
Source: ASPCA

Verdict

Leeks are allium vegetables that contain thiosulfates and organosulfur compounds highly harmful to cats' red blood cells. The entire plant is toxic, including the bulb and green leaves. Cats are particularly vulnerable to allium toxicity due to their limited G6PD enzyme levels. Leeks are frequently used in cooking, so be aware of soups, stews, and casseroles that may contain them.

Symptoms to watch for

  • vomiting
  • diarrhea
  • lethargy
  • pale gums
  • weakness

What to do

Contact your vet. Check all human food before sharing — soups, stews, and stock often contain leeks or onion. When in doubt, don't feed it.

📞 US ASPCA Animal Poison Control: (888) 426-4435

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Data sourced from ASPCA Animal Poison Control

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