Foods Your Cat Should Never Eat, From Onions to Xylitol (Updated October 2026)

Last updated: October 22, 2026. Originally published August 2024. We rechecked this guide against current ASPCA, Merck Veterinary Manual and PetMD information and removed statistics we could not verify.

Key takeaways

• Onions, garlic and chives are among the most dangerous kitchen foods for cats, and cats are the most susceptible pets. Cooked and powdered forms count too.
• Chocolate, coffee, alcohol, raw yeast dough and the sweetener xylitol are also on the ASPCA’s do-not-feed list.
• Raw fish and raw meat carry bacteria, and some raw fish contain an enzyme that destroys vitamin B1.
• If your cat eats something risky, call your vet or the ASPCA Animal Poison Control Center at (888) 426-4435 right away. A fee may apply.

Our cats are curious and love to sniff plates, counters and trash cans. A lot of ordinary human foods can make them sick, and some can be life-threatening. This guide covers the foods that vets and poison-control experts warn about most, what they do and what to do if your cat gets into them.

Photo: “Betty’s Cat” by tormentor4555 via Wikimedia Commons, licensed CC BY-SA 3.0 (https://commons.wikimedia.org/wiki/File:Betty%27s_Cat_-_panoramio.jpg).

At a glance: foods to avoid

Infographic created by Pet Story from ASPCA, Merck Veterinary Manual and PetMD guidance, October 22, 2026.

1. Onions, garlic and chives

Onions, garlic, chives and leeks belong to the Allium family. The ASPCA says they can irritate the gut and damage red blood cells, which can lead to anemia, and that cats are more susceptible than dogs. The Merck Veterinary Manual notes that cats can be affected by raw, cooked, dehydrated or granulated onion and garlic, that garlic is 3 to 5 times more toxic than onion and that toxicosis has been reported in cats after less than a teaspoon of cooked onion. Signs of anemia, such as weakness, pale gums and collapse, can take several days to appear, so do not wait for symptoms before calling your vet.

Many prepared foods hide onion or garlic, including sauces, soups, baby food and seasoned meats, so do not share leftovers.

Image: Boris Grigoriev, “Still Life with Cat and Onions”, public domain, via Wikimedia Commons (https://commons.wikimedia.org/wiki/File:Boris-Grigoriev-Still-Life-with-Cat-and-Onions.jpg).

Source: Merck Veterinary Manual, “Garlic and Onion (Allium spp) Toxicosis in Animals” (https://www.merckvetmanual.com/toxicology/food-hazards/garlic-and-onion-allium-spp-toxicosis-in-animals). Screenshot captured October 22, 2026.

2. Chocolate, coffee and caffeine

The ASPCA explains that chocolate, coffee and caffeine contain methylxanthines, which can cause vomiting, diarrhea, panting, excessive thirst, hyperactivity, abnormal heart rhythm, tremors, seizures and even death. The darker the chocolate, or the stronger the caffeine, the greater the risk. Baking chocolate and cocoa powder are the most concentrated, and white chocolate is the least. Call your vet if your cat eats any, and note the type and amount.

3. Alcohol and raw yeast dough

Alcoholic drinks and foods made with alcohol can cause vomiting, diarrhea, incoordination, difficulty breathing, tremors, coma and death, according to the ASPCA. Because cats are small, a little goes a long way, and alcohol is absorbed quickly, so seek help fast. Raw bread dough is a double risk: it can expand in the stomach and cause painful bloating, and the yeast produces alcohol as it ferments.

4. Grapes and raisins

The ASPCA warns that grapes and raisins can cause kidney damage in dogs, and that the exact toxic substance is still speculative. How they affect cats is less clear, and our earlier version of this post overstated what is known. Because it is uncertain, vets generally advise keeping grapes and raisins away from all pets. If your cat eats some, call your vet for advice.

5. Raw fish, raw meat and raw eggs

Raw meat and raw eggs can carry bacteria such as Salmonella and E. coli, which can make pets and people sick, the ASPCA says. Some raw fish pose a second problem. A PetMD veterinary article explains that raw carp and herring are especially rich in thiaminase, an enzyme that destroys thiamine (vitamin B1). In feeding studies, cats fed these fish developed symptoms in as little as 23 to 40 days. Signs are neurological and include loss of coordination, weakness, falling and eventually seizures. Heat deactivates the enzyme, and thiamine supplementation can reverse the problem if caught in time. Fish should be fully cooked, plain and part of a balanced diet.

6. Other foods the ASPCA lists

• Xylitol is a sweetener in gum, candy, baked goods and some toothpaste. It can cause low blood sugar and liver damage.
• Milk and dairy can cause diarrhea or stomach upset because pets do not make much lactase.
• Salty foods can cause excessive thirst and, in large amounts, serious salt poisoning.
• Fatty foods and nuts can cause vomiting, diarrhea and sometimes pancreatitis.
• Raw bones can injure or block the digestive tract.

Source: ASPCA, “People Foods to Avoid Feeding Your Pets” (https://www.aspca.org/pet-care/aspca-poison-control/people-foods-avoid-feeding-your-pets). Screenshot captured October 22, 2026.

What to do if your cat eats something dangerous

Infographic created by Pet Story from ASPCA and PDSA guidance, October 22, 2026.

1. Take any remaining food away and note what your cat ate, how much and when.
2. Call your veterinarian or an emergency clinic right away. You can also call the ASPCA Animal Poison Control Center at (888) 426-4435, 24 hours a day. A consultation fee may apply.
3. Do not try to make your cat vomit at home unless a vet tells you to. The PDSA, a UK veterinary charity, notes that your vet may give an injection if it is early enough.
4. Keep the packaging so the vet can read the ingredients.
5. Watch your cat closely even if they seem fine, because some problems, such as anemia, show up days later.

Photo: “Aegean cat” by Barc0de via Wikimedia Commons, licensed CC BY 3.0 (https://commons.wikimedia.org/wiki/File:Aegean_cat.jpg).

Keeping your cat safe

• Store onions, garlic, chocolate, alcohol and dough in closed cupboards.
• Use lidded trash cans.
• Tell guests and children not to share food.
• Check labels for xylitol.
• Ask your vet before changing your cat’s diet.

Frequently asked questions

Is tuna safe for cats?

Fully cooked, plain fish is fine for most cats in moderation, but fish should not replace a complete cat food. Ask your vet what suits your cat.

Is a tiny bite of onion okay?

Do not risk it. The Merck manual reports toxicosis in cats after small amounts of cooked onion, and garlic is more potent.

Can cats drink milk?

Many cats cannot digest lactose well and can get diarrhea. Fresh water is the better choice.

What about vegetables?

Some plain vegetables are fine as occasional treats. See our guide on whether cats can eat broccoli.

Related guides

• Can Cats Eat Broccoli?
• Best Cat Water Fountains
• Best Cat Treats and Lickable Treats
• 8 Reasons Why Cat Poop Smells So Bad

Sources

• ASPCA, “People Foods to Avoid Feeding Your Pets” (https://www.aspca.org/pet-care/aspca-poison-control/people-foods-avoid-feeding-your-pets)
• ASPCA Animal Poison Control (https://www.aspca.org/pet-care/animal-poison-control)
• Merck Veterinary Manual, “Garlic and Onion (Allium spp) Toxicosis in Animals” (https://www.merckvetmanual.com/toxicology/food-hazards/garlic-and-onion-allium-spp-toxicosis-in-animals)
• PetMD, “Dietary Deficiencies in Cats: Thiamine and Vitamin A” (https://www.petmd.com/blogs/thedailyvet/ktudor/2012/dec/thiamine-deficiencies-and-excess-vitamin-A-in-cats-diets-29552)
• PDSA, “Onion and Garlic Poisoning in Cats” (https://www.pdsa.org.uk/pet-help-and-advice/pet-health-hub/other-veterinary-advice/onion-and-garlic-poisoning-in-cats)

This article is general information for pet owners, not veterinary advice. If your pet seems sick, or you are unsure, call your veterinarian.