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Garlic and Onion Toxicity in Cats

Learn why garlic and onions should not be fed to cats.

The Allium family, which includes garlic, onions, leeks, chives, shallots, and scallions, is toxic to cats. That means you'll need to be careful not to feed your cat anything containing that family of foods, including in powder, raw, cooked, liquid, or dehydrated form.

Why Is the Onion Family Toxic to Cats?

First, onions and garlic cause nausea and other GI symptoms, like vomiting and diarrhea. But once they've been absorbed into the system, items in the onion family cause even more dangerous problems for cats.

A component of the Allium family damages cats' red blood cells. The damage leads to Heinz bodies being attached to the RBCs, which triggers the body to destroy them. When that happens to a high degree, the cat becomes anemic, which means there aren't enough circulating red blood cells to deliver the proper amount of oxygen to the tissues.

Dogs are similarly affected by Allium toxicity as cats, but cats are more sensitive to lower amounts, in general.

What Are the Signs of Onion and Garlic Toxicity in Cats?

The signs of onion family poisoning in cats are related to anemia and lack of oxygen perfusion to the tissues and can include:

  • Pale or "muddy" gums
  • Weakness
  • Lethargy
  • Poor appetite
  • Fast heart and respiratory rates
  • Labored breathing, panting, or open-mouthed breathing (these signs indicate the condition is an emergency)
  • Drooling
  • Red or brown urine

How Is Onion Toxicity in Cats Diagnosed?

A veterinarian will use the following tools to diagnose garlic or onion toxicity in your cat:

  • A thorough history from you
  • A complete physical exam
  • The results of a CBC blood test

How Is Allium Family Toxicity in Cats Treated?

Treatment for onion and garlic toxicity in cats is mainly supportive. If the anemia is severe, the cat may need a blood transfusion and oxygen therapy.

IV fluids and anti-nausea medications may help the kitty recover faster.

How Can I Prevent Garlic and Onion Toxicity in My Cat?

The best way to prevent this toxicity is to keep human foods away from your cat. That includes securing garbage cans so the cat can't get into them.

Additionally, check the labels of any human food you may give your cat carefully before giving it. That includes baby food and homemade cat treats.

Check here for more information: "Human Foods Toxic to Cats."

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