Through many years of cat caretaking, most of us know never to have lilies, poinsettias, irises, and holly in our homes. And, of course, lots of us know that human medications are the No. 1 cause of cat poisoning — and if you didn’t, consider this your wake-up call for this cat health issue. It’s Poison Awareness Month, after all.

But did you know some of the foods you eat can also be harmful or even fatal to your cat? Here are six of them.

1. Onions and all their spicy little relatives

All of the plants in the Allium family — onions, leeks, chives, garlic, shallots, and ramps — contain a substance called N-propyl disulphide, which destroys a cat’s red blood cells and causes fatal anemia. Some pureed baby foods contain onions, so if you need to feed your cat baby food due to a health crisis, read the ingredient list and make sure it does not contain any onions or onion powder. Onions also appear in many recipes for Thanksgiving Day and other holidays, so those are times to be especially watchful of what your cat gets into.

2. Candy and gum

The artificial sweetener xylitol, which is found in toothpaste and in many sugar-free candies and gums, can cause a dangerous drop in your cat’s blood sugar and even lead to liver failure. Xylitol poisoning symptoms include vomiting, lethargy, lack of coordination, and seizures. Read more about xylitol in this Ask a Vet column from Dr. Eric Barchas.

3. Tuna (and raw fish)

You probably know that your feline friend shouldn’t be eating tuna cat food regularly. But did you know that even human-grade canned tuna can be toxic to cats? First, tuna prepared for humans doesn’t have all the nutrients a cat needs to stay healthy. If you’re feeding her raw tuna instead of canned, be aware that raw tuna, like all raw fish, contains enzymes that destroy thiamine, a B vitamin crucial to your cat’s neurological health, which can lead to seizures or coma. Add to that the fact that tuna is one of the most mercury-contaminated fish swimming in the ocean today, and it’s just better to skip it.

4. Alcoholic beverages

Alcohol has the same effect on your cat’s liver as it does on yours, but since cats are so much smaller, a ridiculously tiny amount can result in a critical slowing of the respiration and heart rate. Just two teaspoons of hard liquor like vodka or whiskey can put a five-pound cat into a coma. Alcohol also changes the blood chemistry and makes it too acidic, which can damage your cat’s kidneys. Wine and beer are as dangerous as hard liquor.

5. Grapes and raisins

Although scientists aren’t sure exactly what makes grapes and raisins toxic to cats, the fact remains that they are. If a cat eats these fruits, kidney failure will result. Even a small amount will make your cat sick.

6. Chocolate

Chocolate contains theobromine, which causes abnormal heartbeat, tremors, seizures, and death. Theobromine is in every kind of chocolate, even white chocolate, but dark chocolate and unsweetened baker’s chocolate are the most dangerous.

These aren’t the only foods that are toxic to cats, but they are the most dangerous. Before you feed your kitty any people foods, we recommend you check with your vet and take a look at the ASPCA Poison Control Center’s website for more information.

Read more about cats and toxic substances:

• Plants and Foods that are Poisonous to Cats
• 15 Common Household Hazards for Cats
• Four Ingestible Hazards for Cats

About JaneA Kelley: Punk-rock cat mom, science nerd, animal rescue volunteer and all-around geek with a passion for bad puns, intelligent conversation, and role-play adventure games. She gratefully and gracefully accepts her status as chief cat slave for her family of feline bloggers, who have been writing their award-winning cat advice blog, Paws and Effect, since 2003.