Toxic plants for cats and dogs: risks and precautions.

Five plants that can cause severe poisoning

Some plants cause stomach upset or drooling; others can cause life-threatening organ damage. These five need particular caution:

Lilies and cats: act within hours

True lilies (Lilium) and daylilies (Hemerocallis) are among the most dangerous plants for cats. The US Food and Drug Administration (FDA) says the whole plant is toxic: stem, leaves, flowers, pollen, and the water in the vase. A cat can be poisoned by grooming pollen off its fur. Dogs that eat these lilies may get a mild stomach upset, but they do not develop kidney failure.

Early treatment greatly improves the outlook. If treatment starts 18 hours or more after the cat ate the lily, the kidney damage is generally permanent. That is why you should never wait to see whether your cat becomes ill.

Not every plant called a lily acts the same way. Peace lilies and calla lilies irritate the mouth but do not cause kidney failure. Lily-of-the-valley and the gloriosa or flame lily are very dangerous to both cats and dogs. Lily-of-the-valley affects the heart, and gloriosa lily can cause failure of several organs.

Aroids and calcium oxalate crystals

Common houseplants in the Araceae family include Monstera deliciosa, Pothos (Epipremnum aureum), Philodendron, ZZ Plant (Zamioculcas zamiifolia), and Dieffenbachia.

These plants contain tiny, needle-shaped insoluble calcium oxalate crystals in cells called idioblasts. Chewing a leaf can release the crystals:

• The released crystals irritate the tongue, roof of the mouth, and throat.
• Immediate Symptoms: Head shaking, pawing at the mouth, cries of pain, heavy drooling, and vomiting.
• Emergency Concern: Swelling can sometimes block the airway and make breathing difficult. Seek emergency veterinary care for breathing problems.

More common plants to know

The ASPCA lists the plants below as toxic to cats and dogs. Most cause stomach upset, but a few can affect the heart or blood. Many of them are sold as gifts or grow in ordinary gardens.

Cardiac glycosides are plant chemicals that change the rhythm of the heart. Oleander, foxglove, and lily-of-the-valley all contain this type of toxin, so treat any chewing on these plants as an emergency.

Kitchen herbs and pets

Herb pots often sit at pet height on a balcony or kitchen sill. The ASPCA lists these common herbs as follows. A “toxic” listing here usually means stomach upset after a large amount, but garlic and chives can cause serious harm.

To grow these herbs in pots, and to place them well in a home with pets, read the culinary herb gardening guide.

Plants listed as non-toxic to cats and dogs

ASPCA lists the following plants as non-toxic to cats and dogs. Chewing any plant can still cause stomach upset; confirm the scientific name when choosing one.

Reduce exposure at home

• Keep potentially toxic plants where pets cannot reach them. A high shelf or hanging pot alone does not guarantee that a cat cannot get to a plant.
• Ask a veterinarian before using a deterrent spray around a pet. Follow the product label; a spray does not replace preventing access to a toxic plant.
• If you want to provide grass for a cat to chew, ask your veterinarian which plants and products are appropriate.
• Check every plant in a bouquet before bringing it into a home with pets. A common name such as lily can refer to plants with different risks; confirm the scientific name.

Garden hazards in a Mediterranean climate

In Lebanon and other Mediterranean countries, several high-risk plants are common in gardens, streets, and courtyards. Dogs that spend time outdoors meet them most often.

• Oleander is planted widely along roads and in gardens. Do not leave oleander prunings where a dog can chew them, and do not burn them.
• Sago palm (Cycas revoluta) is a popular courtyard and pot plant. The ASPCA lists liver failure and death among its effects. Keep dogs away from it completely.
• Castor bean (Ricinus communis) grows as a weed in many warm regions. The ASPCA warns that as little as one ounce (about 28 g) of seeds can be lethal. Signs often start 12 to 48 hours later.

Long, hot summers mean more time outdoors and more pruning. Clear clippings the same day. Check new plants in your garden or your neighbor’s before you let a young dog roam.

Signs that need a veterinarian now

The same sign can have many causes, and you cannot diagnose poisoning at home. This table only shows why each sign deserves a call.

Get veterinary help after a suspected exposure

If your pet ingests a suspected toxic leaf, flower, or berry:

1. Call your emergency veterinary hospital immediately or contact the ASPCA Animal Poison Control Center (24/7 hotline: 1-888-426-4435) or Pet Poison Helpline (1-855-764-7661).
2. Do not give a home remedy or induce vomiting unless a veterinarian specifically instructs you to do so.
3. A clear photo or plant sample may help the veterinarian. Do not delay the call to collect one.

The ASPCA adds these steps:

• Move your pet away from the plant so it cannot eat more.
• Check every pet in the home, even those you think were not involved.
• If your pet vomited, look for plant pieces in the vomit and tell the veterinarian.
• Be ready to give your pet’s species, breed, age, weight, and health problems.

Animal poison hotlines in the United States may charge a consultation fee. Outside the United States, call your own veterinarian or the nearest emergency clinic. Save both numbers in your phone today, and find out which clinic opens at night and at weekends.

Three real situations

A cat and a bouquet

A guest brings stargazer lilies. Next morning, you find orange pollen on your cat’s face. Call a veterinarian straight away and ask whether to wipe the pollen off before you travel. Then take the cat in. Remove the bouquet from the house.

A puppy and a sago palm

Your puppy chews the base of a sago palm in the courtyard. It looks normal an hour later. Call a veterinarian now anyway: liver damage from cycasin can develop later, and early treatment works best.

A dog and oleander prunings

After a summer trim, your dog chews oleander twigs left on the path. Take the dog to a veterinary clinic at once, because oleander can affect the heart. Bring a twig in a bag so the veterinarian can confirm the plant.

When to get expert help

Call a veterinarian or animal poison service whenever your pet chews a plant you cannot name, or any plant in this guide. Go straight to an emergency clinic for collapse, seizures, trouble breathing, or bleeding. A cat that touched a true lily or daylily always needs a veterinarian the same day. For rabbits, birds, reptiles, and other pets, ask a veterinarian who treats that species, because the cat and dog lists may not apply.