Is Winterberry Toxic to Cats?
Also known as: Ilex verticillata, Black Alder, Christmas Berry · Ilex verticillata
What makes it toxic
Saponins and related glycosides concentrated in the bright red berries, with irritants in leaves too. They inflame the stomach and intestines and can depress the nervous system.
Warning signs to watch for
Vomiting, diarrhea, drooling and loss of appetite within a few hours, sometimes with lethargy or a wobbly gait. Severe poisoning is uncommon because the bitter berries limit intake.
What to do if your cat eats it
Remove berries and plant material, offer water and monitor. Call your vet if vomiting repeats or the cat becomes unusually dull or unsteady.
Common questions
Are winterberry branches in holiday decor a risk?
Yes — cut branches hold berries that drop as they dry, and both fresh and dried berries stay toxic. Choose pet-safe decor instead.
Is winterberry worse than American holly?
They carry similar saponins and cause similar signs. Treat all Ilex species as mildly to moderately toxic to pets.
More plants checked for cats
This page is general educational information, not a substitute for professional veterinary advice. Every pet is different — if your animal ate something concerning, contact your veterinarian or a pet poison hotline right away. Checking what your pet can eat? Visit our sister site SafeOrToxic.