Christmas plants poisonous to cats and dogs (and what about kids?)

Pets. The ASPCA lists vomiting and diarrhea, and less often low blood pressure, trouble breathing and a slow heart rate. NC State's American mistletoe page rates the poison severity medium, mostly from eating a lot of berries. Dr. Means notes that serious drops in blood pressure are rare and mostly follow large amounts. The MSD Veterinary Manual is the most serious source: it says every part of American mistletoe is toxic, and that a toxic dose can bring on vomiting, heavy diarrhea, dilated pupils, fast and labored breathing, shock and, within hours, death from heart and circulation collapse. That's why we rate it moderate to severe for pets: most nibbles stay mild, and a large amount is an emergency.

American or European mistletoe? They're different plants. The mistletoe sold in the US is American mistletoe (Phoradendron). European mistletoe (Viscum album) is the more toxic of the two, per Poison Control and the Western Journal of Emergency Medicine review, and it isn't native to or sold in the US. Most of mistletoe's scary reputation comes from European mistletoe, and its serious cases mostly followed herbal teas. The MSD Veterinary Manual's pet entry covers American mistletoe only. Neither plant is safe for pets, so treat any mistletoe the same way.

Kids. Poison Control explains that the mistletoe sold for decorating in the US is American mistletoe, which is less toxic than European mistletoe. In a study of 1,754 exposures, most of them children, almost no one had symptoms and no one died. The California Poison Control System says one or two berries or leaves eaten by a child are unlikely to cause serious harm. Both suggest hanging it in netting or a bag, and Poison Control adds: never use it to decorate food.

Holiday bouquets often include lilies, and the ASPCA's holiday safety tips call many of them highly toxic to cats. The ASPCA's Easter lily entry lists vomiting, loss of appetite, low energy and kidney failure, and says death is possible. Cats are the only animals known to be affected that way.

The US Food and Drug Administration (FDA) names the usual suspects: Asiatic, Easter, Japanese show, Oriental, rubrum, stargazer, tiger and wood lilies, plus daylilies. Every part counts, including pollen and the water in the vase. Early signs show up within 12 hours, kidney failure can follow within 3 days, and waiting 18 hours or more before treatment usually means lasting kidney damage. The FDA's advice is simple: in a home with cats, leave these lilies out of the bouquet.

Dogs don't get kidney failure from these lilies; the FDA says they may get a mild upset stomach. Peace lilies and calla lilies belong to a different plant group: they irritate the mouth and don't cause kidney failure, per the FDA.

The tree. The ASPCA says Christmas trees aren't particularly toxic, and it asks you to anchor the tree so a climbing cat or a bumping dog can't tip it over. Dr. Means explains that fir, pine and spruce contain oils that can cause vomiting, a poor appetite or belly pain, usually mild and short. The needles can also scratch the mouth and gut, and a pet that eats a lot of them can end up with a blockage. Poison Control also describes a dog that gagged and coughed on swallowed needles. For people, the California Poison Control System says pine, spruce and fir needles aren't poisonous, though they can be a choking risk for small children.

The water. The ASPCA's holiday safety tips say tree water breeds bacteria that can cause nausea, diarrhea or an upset stomach, so keep it covered or out of reach. Poison Control agrees and adds:

• Store-bought preservatives usually contain fertilizer and sugar. In the small amounts kids and pets usually drink, they cause stomach upset at most.
• Homemade mixes can be riskier. Recipes with aspirin, bleach or alcohol include ingredients that are harmful to children and pets.
• Plain water is all the tree needs. The National Christmas Tree Association recommends nothing else, and our Christmas tree care guide explains how to keep a tree fresh with it.

Prefer a tree that's safe for pets and still alive in spring? A Norfolk Island pine is listed as non-toxic to cats and dogs, and our living Christmas trees guide covers it.

Myth: poinsettias are deadly. The ASPCA lists the poinsettia as toxic to cats, dogs and horses, and calls it generally over-rated in toxicity: the milky sap irritates the mouth and stomach and sometimes causes vomiting. In a review of 22,793 poinsettia exposures reported to US poison control centers, 92% caused no symptoms, and none were fatal. The Western Journal of Emergency Medicine review traces the scary story back to a single, unconfirmed death in 1919. Poison Control adds that researchers couldn't find a poisonous dose even at about 500 to 600 leaves. So a poinsettia is fine in a home with pets and kids, kept out of reach. Our poinsettia care card has the full answer.

Myth: mistletoe kisses come with a death risk. The American mistletoe sold in the US caused no deaths among 1,754 exposures, per Poison Control and the same review, and the rare deaths on record came from brewed mistletoe tea. It's still toxic to pets, so keep the netting on.

Myth: with lilies, only a bite of the flower matters. The FDA says pollen and vase water are enough to harm a cat.

Myth: "non-toxic" means a pet can snack on it. The Christmas cactus, rosemary, moth orchid and Norfolk Island pine are on the ASPCA's non-toxic list, and their care cards still warn that eating enough of any plant can upset a pet's stomach.