Philodendron in Pets

Philodendron leaves contain oxalate crystals that sting a pet's mouth. Learn what is normal after a bite, simple ways to soothe the mouth and when to call a vet urgently.

What It Is

Philodendrons are climbing and trailing houseplants with heart-shaped or deeply split leaves. Like other members of the arum family, they contain bundles of insoluble calcium oxalate crystals that pierce the lining of the mouth when a leaf is bitten, along with irritating proteins.

Where Pets Come Across It

Heartleaf philodendron trailing from shelves and hanging baskets, split-leaf types in large floor pots, and cuttings rooting in jars of water on windowsills, which cats often investigate.

Which Animals Are Affected

Cats are most often affected because they chew trailing leaves; dogs and other pets can also react.

Published Toxic Dose

There is no toxic dose to calculate: the reaction is a local injury from crystals, and the Merck Veterinary Manual reports no body-wide reaction to insoluble calcium oxalate. So the calculator only records the amount and asks you to call.

Signs and How Soon They Appear

Immediate mouth pain, drooling, pawing at the face, vomiting and loss of appetite. Pet Poison Helpline notes rare cases of throat swelling that affects breathing.

What to Do Right Now

Rinse the mouth with water and wipe away plant pieces. A small amount of milk or a tasty food can help wash crystals off the tongue. Call your vet if signs last more than a few hours or at once if breathing is affected. No need to induce vomiting.

Telling philodendron from pothos

Heartleaf philodendron and golden pothos are often sold under each other's names. Philodendron leaves are thinner and softer, with a slim stalk and new leaves that emerge wrapped in a papery sheath (cataphyll) that later browns and falls off. Pothos leaves are thicker and waxier, often marbled with yellow or white, with a groove along the leaf stalk. For your cat the distinction matters little, because both carry the same kind of crystals, but it helps you look up the right plant. To prevent repeat chewing, train vines up a moss pole or keep pots on high shelves that your cat cannot jump to, and offer cat grass as an alternative. Plants the ASPCA lists as non-toxic, such as spider plant, Boston fern and parlour palm, are safer choices for homes with plant-chewing cats.

Split-leaf and self-heading philodendrons

Large philodendrons such as 'Xanadu' and the tree philodendron (Thaumatophyllum bipinnatifidum, formerly Philodendron selloum) have deeply lobed leaves on thick stalks and are popular as statement floor plants and in subtropical gardens. Their sturdy stems and aerial roots attract dogs that like to gnaw, and because they contain more tissue per bite than a trailing heartleaf vine, a dog can end up with a sore, swollen mouth. Fallen leaves on patios are a common source. Place large pots where dogs cannot lie beside them, clear dropped leaves, and remember that cuttings shared with friends carry the same crystals.

Frequently Asked Questions

Sources and References

• Pet Poison Helpline: Philodendron
• Merck Veterinary Manual: Houseplants and Ornamentals Toxic to Animals

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