Although the milky white sap of poinsettias contains chemicals known as diterpenoid euphorbol esters and saponin-like detergents, poinsettias themselves are not very toxic to cats. If consumed, these substances will upset the digestive system and may result in vomiting, drooling, or, in rare cases, diarrhea. When the milky sap comes into contact with skin, it can cause dermal irritation, which can cause redness, swelling, and itching. In rare cases, exposure to the eyes can cause mild conjunctivitis, or “pink eye” due to inflammation. Signs are self-limiting and don’t require medical treatment unless severe.
Cats may also be poisoned by other Yuletide plants like mistletoe and holly berries. The potentially toxic compounds (saponins, methylxanthines, and cyanogens) and spiny leaves of Christmas or English holly can cause severe gastrointestinal distress when consumed. Because of the mechanical harm caused by the spiny leaves, most cats lip-smack, drool, and shake their heads excessively if they consume it. While most of us hang mistletoe high enough to keep our cats from reaching it, it can still be poisonous if consumed. Fortunately, American mistletoe is not as toxic as its European counterparts. Although mild symptoms of gastrointestinal irritation are observed, large-scale ingestion has also been linked to reports of collapse, hypotension, ataxia (driving while intoxicated), seizures, and even death. See your veterinarian if you think your cat may have consumed any of these plants.
This holiday season, be cautious about the plants you bring into your home if you own a cat. Mistletoe, holly berries, lilies, and poinsettias are all bad for your feline family members.
If you want more information on toxic plants for cats, you can visit the American Society for Prevention of Cruelty to Animals (ASPCA) Poison Control website at https://www.aspca.org/pet-care/animal-poison-control
Of all of these festive plants, lilies are the most toxic and are potentially fatal if ingested by cats. Any part of the plant, including the pollen, flower, stems and leaves are poisonous. These plants belong to the Lilium or Hemerocallis family, with examples being the tiger, day, Asiatic hybrid, Easter, Japanese Show, rubrum, stargazer, red, Western, and wood lilies. If ingested, these lilies can cause kidney failure in cats, with sudden onset of lethargy, decreased appetite, vomiting and either increased or decreased thirst and urination with dehydration. If you suspect your cat has eaten any part of a lily plant then take him directly to your veterinarian as emergency care is needed. The best advice is not to bring any lilies into your home if you have cats, and be sure to inspect any bouquets of flowers that are delivered to your home, as lilies are the #1 flower used by florists!
“Despite the widespread belief that poinsettia plants are toxic to animals, household pets are not harmed by them unless they consume a significant amount of their leaves and bracts.” When cats chew on leaves, some of them may salivate and throw up if they swallow any of the leaves. It’s a good idea to keep newly brought plants out of reach because cats and puppies love to chew on them.”
The Colorado State Extension site has an extensive review of poinsettia history and cultural requirements at: https://extension.colostate.edu/topic-areas/yard-garden/poinsettias-7-412/
They have a section on studies showing that while poinsettia is not toxic, eating it may make you uncomfortable. Naturally, people who are allergic to the plant’s natural latex should stay away from it.
The College of Veterinary Medicine at Washington State University, provides the following information for Poinsettia, as well as Mistletoe and Holly. “Holiday Health Hazards” (https://hospital.vetmed.wsu.edu/2021/11/23/holiday-health-hazards-for-pets/)
“Poinsettias fill homes with color during the holidays. Although poinsettias have a negative reputation, they are not particularly toxic to pets. Although they do have a milky sap that can irritate the mouth, the symptoms are usually not severe.