Toxic Plants and Household Dangers for Cats: Lilies, Medications, Oils and More

Cats are curious, they groom constantly, and their bodies process some substances very differently from ours or even from dogs'. That means some ordinary household items, from a bouquet of flowers to a single dropped painkiller, can be life-threatening.

Bookmark the next section. In a poisoning emergency, speed matters more than anything else.

If you think your cat has been poisoned

Don't try home remedies such as milk, oil, or activated charcoal unless directed by a veterinarian. If a substance is on your cat's fur, such as a flea product or essential oil, call for advice before doing anything; you may be told to wash the area with lukewarm water and a mild liquid dish soap, and to prevent your cat from grooming it off in the meantime.

Lilies: the most dangerous plant for cats

If you remember one thing from this guide, make it this: true lilies and daylilies can cause fatal kidney failure in cats, and any exposure is an emergency.

Which lilies are dangerous

• True lilies (genus Lilium), including Easter lilies, tiger lilies, Asiatic lilies, Oriental lilies such as stargazers, Japanese show lilies, rubrum lilies and wood lilies.
• Daylilies (genus Hemerocallis), which are common in gardens and landscaping.

Every part of these plants is toxic: petals, leaves, stems, flowers, pollen and even the water in the vase. A cat doesn't need to eat a whole flower. Chewing a leaf or two, drinking vase water, or grooming a little pollen off their fur can be enough.

Signs of lily poisoning

Early signs can include vomiting, drooling, loss of appetite, lethargy and hiding. These may appear within hours and then seem to fade, but kidney damage continues. Without treatment, kidney failure can develop within a few days. Don't wait for signs. If you know or suspect your cat has had any contact with a lily, take them to a veterinarian immediately and take the plant with you. Early, aggressive treatment, which usually involves decontamination and hospitalization on intravenous fluids, gives the best chance of recovery. Delays can be fatal.

Other "lilies"

• Lily of the valley (Convallaria majalis) isn't a true lily, but it contains compounds that affect the heart and can cause dangerous heart rhythm problems. Exposure is also an emergency.
• Peace lilies (Spathiphyllum) and calla lilies (Zantedeschia) aren't true lilies either. They contain insoluble calcium oxalate crystals that irritate the mouth and throat, causing drooling, pawing at the face and vomiting, but they don't cause the same kidney failure. Call your vet for advice.

Keeping cats safe from lilies

• Don't bring true lilies or daylilies into a home with cats, even in a room the cat "never" goes into.
• Check bouquets and flower arrangements carefully. Lilies are very common in florist bouquets, sympathy arrangements and holiday displays, especially around Easter and Mother's Day.
• Let friends and family know, so they don't send lilies as a gift.
• If your cat goes outdoors, avoid planting daylilies or true lilies in your garden.

Other plants to keep away from cats

Many plants can cause problems if cats chew them, ranging from mild stomach upset to organ failure. This is not a complete list. The ASPCA maintains a searchable list of toxic and non-toxic plants, and it's worth checking any plant before bringing it home. Common names can be misleading, so look up the scientific name if you can.

Plant	Main concern
Sago palm (Cycas revoluta)	All parts, especially the seeds, can cause severe liver failure. An emergency.
Oleander, foxglove, lily of the valley	Heart rhythm problems. An emergency.
Autumn crocus (Colchicum)	Severe vomiting and diarrhea, and damage to multiple organs. An emergency.
Castor bean	Extremely toxic seeds. An emergency.
Azaleas and rhododendrons	Vomiting, drooling and weakness; heart effects in larger amounts.
Tulips, hyacinths and daffodils	Vomiting, drooling and diarrhea; the bulbs are the most toxic part.
Kalanchoe	Vomiting and diarrhea; heart effects are possible.
Dieffenbachia, philodendron, pothos, monstera	Mouth irritation, drooling, pawing at the mouth and vomiting.
Aloe vera	Vomiting and diarrhea.
Cyclamen	Vomiting and diarrhea; the tubers are most toxic.
Chrysanthemums	Vomiting, drooling and wobbliness.
Mistletoe and holly	Stomach upset; mistletoe can be more serious in larger amounts.
Poinsettia	Mild mouth and stomach irritation. Its reputation is worse than its bite, but it's still best kept out of reach.
Cannabis (including edibles)	Wobbliness, lethargy, dribbling urine and, rarely, more serious effects. Edibles may also contain chocolate or other harmful ingredients.

Cat-friendlier choices

If you love houseplants, there are many that the ASPCA lists as non-toxic to cats, including the spider plant (Chlorophytum comosum), Boston fern, parlor palm, areca palm, prayer plants and calatheas, African violets, moth orchids (Phalaenopsis), Christmas cactus and haworthia. Watch for look-alike names: the Boston fern is listed as non-toxic, but the asparagus fern is not. Cat grass (usually oat, wheat or barley grass) gives many cats something they're allowed to chew.

"Non-toxic" doesn't mean edible. Any plant can cause a little vomiting if a cat eats enough of it, and plants may be treated with fertilizers or pesticides. If your cat is a determined chewer, hanging planters and plant-free rooms can help.

Dog flea and tick products (permethrin)

Many spot-on flea and tick treatments made for dogs, and some dog sprays, shampoos and collars, contain permethrin or related compounds called pyrethroids. Dogs tolerate them well. Cats don't: they can't break permethrin down efficiently, and a concentrated dog product can cause severe poisoning in a cat, even in small amounts.

Cats are most often poisoned when:

• An owner applies a dog spot-on to a cat, sometimes thinking a "small dose" will be fine. It won't.
• A cat grooms, cuddles or sleeps against a dog who has just been treated.
• A cat licks a spill of the product.

Signs of permethrin poisoning

Signs can start within a few hours and include twitching, muscle tremors, sensitivity to touch or sound, drooling, wobbliness, dilated pupils, a high body temperature and seizures. Permethrin poisoning can be fatal, but cats who are treated promptly often recover. It is an emergency: contact a veterinarian immediately, and bring the product packaging.

Prevention

• Use only parasite products that are specifically labeled for cats, and preferably ones recommended by your veterinarian.
• Never split or "share" a dog product with a cat.
• Check the weight range on the package. Products for large cats aren't safe for small kittens.
• If you have both cats and dogs, ask your vet whether a different product would be safer for your dog. If you do use a permethrin product on your dog, keep cats away from the dog until the product is fully dry, or for as long as the label directs.
• Be wary of "natural" flea products too; some contain essential oils that are also risky for cats.

Acetaminophen and other human medications

Human medications are among the most common causes of poisoning in pets. Cats are small, and their liver handles many drugs differently from ours, so a dose that is safe for a person can be lethal for a cat.

Acetaminophen (Tylenol, paracetamol)

Acetaminophen is extremely dangerous to cats. They lack enough of a liver enzyme needed to process it safely, and it damages their red blood cells, so their blood can no longer carry oxygen properly, and it can harm the liver. A single tablet can kill a cat. Signs include brown, gray or bluish gums, difficulty breathing, swelling of the face and paws, drooling, vomiting, lethargy and dark urine. Acetaminophen is in many cold, flu and combination pain products, so read labels carefully. Any exposure is an emergency.

Other painkillers

Ibuprofen (Advil, Motrin), naproxen (Aleve) and similar anti-inflammatory drugs can cause stomach ulcers and kidney failure in cats. Aspirin is also dangerous for cats unless prescribed and dosed precisely by a veterinarian. Pain-relief creams and gels can be a problem too: cats have become seriously ill after licking a person's skin where an anti-inflammatory cream had been applied.

Other medications to guard

• Antidepressants and anti-anxiety medications. Some cats seem drawn to certain antidepressant capsules.
• ADHD medications and other stimulants.
• Sleep aids, heart and blood pressure medications, and thyroid medications.
• Hair-regrowth products containing minoxidil, which are extremely dangerous to cats even through contact with treated skin, hair or pillows.
• Hormone creams and other topical medications.
• Cold and allergy remedies, especially those containing decongestants.
• Vitamins and supplements, including vitamin D and iron.

Prevention

• Keep all medications in closed cabinets, not on nightstands, counters or in open bags.
• Take pills over a counter or sink, and search for any you drop immediately.
• Keep human and pet medications in separate places to avoid mix-ups.
• Wash your hands after applying creams, and keep cats away from treated skin as your doctor or pharmacist advises.
• Never give your cat any medication, human or pet, without your veterinarian's specific instruction.

Essential oils, diffusers and liquid potpourri

Essential oils are highly concentrated plant extracts, and cats are especially sensitive to many of them. Like acetaminophen, part of the reason is that cats lack some of the liver enzymes needed to break down certain compounds. Exposure can happen through licking oil off the fur or skin, through the skin itself, or by breathing in droplets.

Oils of particular concern

Tea tree oil (melaleuca) is one of the oils most often linked to serious poisoning in cats, sometimes after owners apply it to treat fleas or skin problems. Other oils commonly listed as dangerous to cats include eucalyptus, wintergreen, sweet birch, pennyroyal, peppermint, cinnamon, clove, citrus, pine and ylang ylang. This isn't a complete list, and blends may contain several.

Signs of essential oil poisoning

Drooling, vomiting, wobbliness, tremors, weakness, difficulty breathing, coughing or wheezing, pawing at the face, and redness or burns on the lips, tongue or skin. If your cat has been exposed, call your veterinarian or a poison hotline right away.

Diffusers and potpourri

• Active diffusers, such as ultrasonic and nebulizing diffusers, release fine droplets of oil into the air. These can settle on a cat's fur and be swallowed during grooming, and inhaling them can irritate the airways. Cats with asthma or other breathing problems are especially at risk.
• Reed diffusers and oil warmers can be knocked over and spilled, and cats may walk through spills and lick their paws.
• Liquid potpourri often contains both essential oils and detergents that can cause chemical burns in the mouth and throat. Keep it out of homes with cats.

The safest approach is to never apply essential oils to your cat and to avoid diffusing them in spaces your cat uses. If you choose to use them, keep bottles tightly closed and out of reach, use them only briefly in a well-ventilated room your cat can leave, and stop immediately if your cat shows any signs of discomfort. "Natural" does not mean safe for cats.

String, thread and other linear foreign bodies

Cats love playing with string, and their tongues are covered in tiny backward-facing barbs that make it easy to swallow but hard to spit out. Swallowed string, thread or ribbon can become what veterinarians call a linear foreign body. One end catches, often under the tongue or in the stomach, while the intestines try to move the rest along. The gut bunches up around the string like fabric on a drawstring, and the string can cut through the intestinal wall. This is a surgical emergency.

Common culprits

• Sewing thread, especially with a needle attached.
• Yarn and embroidery floss.
• Ribbon, curling ribbon and gift-wrap string.
• Tinsel and holiday garlands.
• Dental floss.
• Rubber bands, hair ties and elastic.
• Strings from wand toys, roasts, tea bags and blinds.

Signs of a linear foreign body

Vomiting, often repeated; not eating; lethargy; a painful belly, which may show as hunching or not wanting to be picked up; diarrhea or straining; and drooling. Signs can start soon after swallowing or develop over days. Any cat who is vomiting repeatedly or has stopped eating needs to see a veterinarian.

Prevention

• Put sewing and knitting supplies away in closed containers.
• Store wand toys out of reach after play.
• Skip tinsel, and supervise gift-wrapping sessions.
• Pick up hair ties, rubber bands and floss, and use a lidded bathroom trash can.
• Tie up or remove looped cords on blinds and curtains.

Other everyday hazards

Chemicals

• Antifreeze (ethylene glycol). It tastes sweet, and a very small amount, even licked from a puddle or from paws, can cause fatal kidney failure. Early signs may look like drunkenness and then appear to improve while kidney damage continues. Treatment must begin within hours to have the best chance of working. Clean spills immediately, store antifreeze tightly closed, and be aware that some decorative snow globes contain it.
• Rodent poisons. Different products cause internal bleeding, brain swelling or kidney failure, and signs can be delayed by days. Cats can be poisoned by eating bait or, with some products, by eating a poisoned rodent. Keep the packaging, because treatment depends on the exact ingredient.
• Insecticides and garden products, including slug and snail bait, which can cause tremors and seizures, as well as fertilizers and weed killers. Follow labels and keep cats away from treated areas.
• Cleaning products. Concentrated bleach, some disinfectants and pine oil cleaners, drain cleaners and oven cleaners can cause burns or poisoning. Cats can be exposed by walking across a wet floor and licking their paws. Store products closed, dilute as directed, rinse surfaces where appropriate, and let floors dry before cats walk on them.

Foods

Onions, garlic, leeks and chives (in any form, including powders) can damage a cat's red blood cells. Chocolate, caffeine, alcohol, raw yeast dough, grapes and raisins, and products containing xylitol should also be kept away from cats. Our feeding and nutrition guide covers dangerous foods in more detail.

Physical hazards

• Open windows and balconies. Cats can and do fall from windows and balconies, often while chasing a bird or insect. Use secure screens and don't leave cats unsupervised on balconies.
• Washers and dryers. Cats love warm, dark spaces. Keep doors closed and check inside before every load.
• Recliners and sofa beds. Check underneath before reclining or folding.
• Electrical cords. Chewing can cause burns to the mouth and serious injury. Cover or hide cords, especially with kittens.
• Batteries. Button and coin batteries can cause severe internal burns if swallowed.
• Small objects. Hair ties, small toy parts, bottle caps and earplugs can cause intestinal blockages.
• Plastic bags. Cut the handles off any bags left out for play, and keep other bags put away.
• Heat sources. Stovetops, candles, space heaters and fireplaces. Use guards and never leave a flame unattended with a cat in the room.
• Car engines and garages. In cold weather, cats may shelter under the hood. Tap the hood before starting the car, and check before closing the garage.

A quick cat-proofing routine

A once-over every few months, and before holidays, catches most hazards.

• Living room: check plants and bouquets for lilies and other toxic species; tidy cords; check recliners; remove liquid potpourri and active diffusers from cat areas.
• Kitchen: store onions, garlic, chocolate and medications out of reach; keep the trash covered; check the dishwasher and fridge before closing.
• Bathroom: close medicine cabinets; keep the toilet lid down; use a lidded trash can for floss and razors; store hair-regrowth and other topical products safely.
• Bedroom: put away hair ties, jewelry and pills from the nightstand.
• Laundry: close washer and dryer doors; store detergent pods sealed.
• Craft area: sewing kits, yarn and ribbon in closed containers.
• Garage and garden: antifreeze, rodent poisons, slug bait and garden chemicals stored securely; no lilies in the garden.
• Pet supplies: keep dog flea products separate from cat products, and save poison hotline numbers in your phone.

If you're bringing a new cat or kitten home, our guide to the first week and the new cat checklist include more preparation tips.

Key takeaways

• Any contact with a true lily or daylily, including pollen or vase water, is an emergency. Keep lilies out of homes with cats.
• Never use dog flea or tick products on cats. Permethrin can kill a cat.
• Never give acetaminophen or any human medication to a cat. A single tablet can be fatal.
• Don't apply essential oils to cats, and avoid diffusing them where cats live.
• Never pull string from a cat's mouth or bottom. Go to a vet.
• Store antifreeze, rodent poisons and cleaning products securely, and check appliances and recliners before use.
• In a suspected poisoning, call your vet, an emergency clinic, or a poison hotline immediately, bring the packaging, and don't induce vomiting at home.