✕ Toxic

Mistletoe

Q: Is Mistletoe toxic to cats?

Warning: Toxic. Mistletoe (Phoradendron spp. or Viscum spp.) is a popular holiday decoration that is highly toxic to cats. It contains toxic proteins, such as lectins and phoratoxins, which can seriously affect a cat's stomach, intestines, and heart. The berries usually have the highest concentration of these toxins. If a cat eats mistletoe, it may experience severe vomiting, diarrhea, drooling, and stomach pain. The toxins can also cause dangerous drops in blood pressure and a slowed heart rate, which can make the cat very weak or cause breathing problems. Even dried decorations or fallen berries are dangerous. Keep all mistletoe completely out of your cat's reach during the holidays. If you suspect your cat has eaten any part of a mistletoe plant, contact a veterinarian immediately.

Phoradendron spp. or Viscum

Mistletoe (Phoradendron spp. or Viscum spp.) is a popular holiday decoration that is highly toxic to cats. It contains toxic proteins, such as lectins and phoratoxins, which can seriously affect a cat's stomach, intestines, and heart. The berries usually have the highest concentration of these toxins. If a cat eats mistletoe, it may experience severe vomiting, diarrhea, drooling, and stomach pain. The toxins can also cause dangerous drops in blood pressure and a slowed heart rate, which can make the cat very weak or cause breathing problems. Even dried decorations or fallen berries are dangerous. Keep all mistletoe completely out of your cat's reach during the holidays. If you suspect your cat has eaten any part of a mistletoe plant, contact a veterinarian immediately.

Important Notes

Toxic compounds: phoratoxins (toxic lectins) in all parts; viscotoxins in European Mistletoe; berries most concentrated

Mechanism: lectins inhibit protein synthesis in cells; cardiovascular effects include bradycardia and hypotension

Symptoms: vomiting, diarrhea, drooling, abdominal pain, weakness, bradycardia, low blood pressure; severe ingestion may cause collapse

All parts are toxic — fresh plant, dried decorations, and even fallen berries on the floor

Keep mistletoe completely out of reach during the holiday season; contact your vet if ingestion is suspected

Potentially Toxic Parts

Leaf

Fruit

Possible Symptoms Reported in Cats

Slowed heart rate (bradycardia), low blood pressure (hypotension), and potential cardiovascular collapse

Cardiac · Within hours of ingesting a toxic dose

Gastrointestinal upset, including vomiting and diarrhea (which can be profuse)

Gastrointestinal · Within hours of ingestion

Difficulty breathing or rapid, labored breathing

Respiratory · Within hours of ingesting a toxic dose

Weakness, odd behavior, and dilated pupils

Gastrointestinal · Within hours of ingestion

Disclaimer: This summary was compiled from multiple sources and is for informational use only. It is not a diagnosis or treatment plan. Toxicity can vary based on the substance, amount, plant part, and individual cat. If you think your cat may have been exposed to a toxic substance, contact a veterinarian right away.