Is Philodendron Poisonous? Risks for Humans, Cats, and Dogs

Philodendron is toxic to humans, cats, dogs, and horses. The plant contains insoluble calcium oxalate crystals that cause immediate burning and irritation in the mouth and throat when chewed or ingested. Serious poisoning is rare; the intense oral pain usually stops further eating, but any significant exposure warrants a call to Poison Control.

What Is Philodendron?

Philodendron is one of the most common houseplants in the world, found in nearly every garden center and big-box home store. With over 450 species, it covers everything from trailing vines to compact floor plants. The heartleaf philodendron (Philodendron hederaceum) is the most widely sold variety, but Brasil, Birkin, and Xanadu are also common indoors.

One naming note worth knowing: “split-leaf philodendron” is a label nurseries apply to both Thaumatophyllum bipinnatifidum and Monstera deliciosa. These are different genera, but both contain calcium oxalate crystals and are toxic by the same mechanism. If you bought a “split-leaf philodendron” and it has fenestrations (holes in the leaves), you likely have a Monstera. The toxicity advice on this page applies equally to both.

All parts of the plant are toxic. Leaves are the primary contact point because they are the most accessible part, especially for cats and young children.

Is It Poisonous?

Yes. Philodendron is toxic to humans, cats, dogs, and horses, per the ASPCA classification for all three species.

The good news is that the pain response starts immediately on contact, which naturally limits how much a child or pet will ingest. Severity sits in the moderate irritant category: painful and distressing but not typically life-threatening. Philodendron is not in the same danger tier as rosary pea, oleander, or lily, but it is not trivial either. Children and small pets are at higher risk because a smaller ingested amount causes proportionally more effect.

The Toxin: Calcium Oxalate Crystals

The active agent is insoluble calcium oxalate, which forms microscopic needle-like crystals called raphides. These crystals are stored in specialized plant cells. When the plant is bitten or crushed, those cells eject the raphides mechanically into the soft tissue of the mouth and throat. The physical puncturing is what causes the immediate burning, not a slow-acting systemic toxin.

This is an important distinction: raphides cause pain instantly because they are physically embedded in tissue, not because a chemical is absorbed into the bloodstream. That is why rinsing with cool water helps: it flushes out crystals before they can cause further irritation.

Philodendron is less severe than dieffenbachia, which releases proteolytic enzymes alongside raphides. Philodendron relies primarily on the crystal mechanism, making it somewhat less damaging with equivalent exposure.

Sap from the plant also irritates skin and eyes on contact, independent of ingestion.

Symptoms of Poisoning

Onset is immediate: within seconds to minutes of contact.

Ingestion (humans and children):

• Intense burning or stinging in the mouth and throat
• Swelling of lips, tongue, and mouth
• Excessive drooling or foaming
• Nausea and vomiting
• Difficulty swallowing
• Loss of voice (rare, with significant swelling)
• Airway obstruction (very rare; seek emergency care immediately if breathing is affected)

Ingestion (cats and dogs):

• Pawing at the mouth and face (typically the first sign)
• Drooling and retching
• Vomiting
• Decreased appetite and lethargy
• Difficulty swallowing
• Airway swelling (rare but possible; seek emergency vet care immediately)

Skin contact:

• Rash, redness, and swelling at the contact site
• Dermatitis with repeated or prolonged exposure
• Wash off promptly; sap is the primary skin irritant

Eye contact:

• Redness, pain, and burning
• Tearing
• Corneal abrasions from raphide crystals
• Rare permanent eye damage if not flushed promptly

Timeline: With basic first aid, oral symptoms typically resolve within 30 minutes to 24 hours.

What to Do If Exposed

Humans:

1. Remove any plant material from the mouth.
2. Rinse the mouth thoroughly with cool water and spit. Do not swallow the rinse water.
3. Suck on ice chips or a frozen treat to reduce swelling and numb pain (recommended by Poison Control).
4. Call Poison Control: 1-800-222-1222.
5. For eye contact: flush with lukewarm water for at least 15 minutes; seek medical attention if pain persists.
6. For skin contact: wash with soap and water for at least 15 minutes.
7. Go to an emergency room if breathing is affected, swallowing becomes impossible, or symptoms worsen.

Pets:

1. Remove the animal from the plant. Remove any plant material from the mouth if it is safe to do so.
2. Offer fresh water. Do not force it.
3. Call ASPCA Poison Control: (888) 426-4435, or your emergency vet.
4. Do not induce vomiting at home unless directed by a vet.
5. Go to an emergency vet if the animal is having difficulty breathing or cannot swallow.

Safe Handling

• Wear gloves when repotting or pruning; wash hands after any contact.
• Place plants on high shelves or in rooms inaccessible to pets and young children.
• Wipe up fallen leaves promptly; cats are often attracted to fallen plant material.
• The trailing vines of heartleaf philodendron are especially accessible to cats; hanging planters reduce that risk.
• Wash hands before touching your eyes or face after handling any philodendron.

Frequently Asked Questions

Can a philodendron kill a cat? Severe cases are rare and deaths from philodendron are not well documented, but the symptoms are distressing. Call a vet for any confirmed ingestion.

Can a philodendron kill a dog? Same as cats. Unlikely to be fatal, but warrants vet contact, especially in small dogs.

Is philodendron poisonous to humans? Yes. It causes burning, swelling, and gastrointestinal irritation. It is most dangerous to young children who ingest a significant amount.

Is split-leaf philodendron (Monstera) poisonous? Yes. Monstera deliciosa contains the same calcium oxalate crystals and is toxic in the same way, despite being a different genus.

Are all philodendrons equally toxic? All species contain calcium oxalate. Some variation exists in crystal concentration between species, but treat all as toxic.

What if my child just touched the leaf and did not eat it? Skin contact typically causes only mild irritation. Wash the area with soap and water. Call Poison Control if a rash develops or the child rubs their eyes.

Is philodendron sap dangerous to skin? Yes. Wash it off promptly. Repeated exposure can cause dermatitis.