Plants That are Toxic to Cats

Bouquets and plants make wonderful gifts and decorations for our homes. However, many plant species can be hazardous to your cat’s health. Be aware of the plants you are bringing into your home to prevent accidental poisoning. Here are several common plants that are toxic to cats:

Aloe

The gel inside the aloe leaf is not toxic, but the white sap contains compounds that are strong emetics (they induce vomiting). Common clinical signs of ingestion include vomiting, diarrhea, and lethargy. Large ingestions can cause reddish-colored urine, muscle tremors, and possible kidney inflammation. 

Exposure to aloe typically requires minor symptomatic care (management of discomfort and care for the outward signs) such as anti-nausea medication and fluids, if the pet is dehydrated.

Chrysanthemums and Daisies

Exposure to mums and daisies may only result in stomach upset. However, these flowers contain low amounts of pyrethrins, which are toxic to cats in large enough quantities. A large exposure to chrysanthemums can result in depression of the central nervous system and ataxia (lack of muscle control), along with gastrointestinal distress. Clinical signs develop within minutes to hours of exposure. Treatment is symptomatic and supportive.

Daffodils (Narcissus sp.)

Daffodils contain toxins that can cause severe digestive upset and, in rare cases, affect the heart and nervous system. These toxins are present in all parts of the plant but are concentrated in the bulb. Minor ingestion of the leaves, stem, or flower can cause stomach upset. Large ingestions of plant material or the bulb can result in more severe clinical signs, including heart and nervous system changes. Clinical signs can develop within minutes or up to 24 hours.

Treatment may depend on the amount ingested and the severity of the clinical signs. Cats exposed to small amounts may only require minor supportive care for stomach upset. Large ingestions of plant material or bulbs may require decontamination and symptomatic and supportive care. Severe clinical signs can last several days.

Kalanchoe

Kalanchoes have brightly colored flowers and are a common household plant. Unfortunately, they contain toxic substances  that affect the heart. The toxins are most concentrated in the flowers but present in all parts of the plant. Minor exposure may only result in stomach upset. If a large amount of this plant is ingested, heart and nervous system signs may also develop within a few hours. Rarely, cardiovascular collapse and sudden death can occur.

For large exposures or those that are symptomatic, treatment may include decontamination, heart monitoring, and other supportive care as needed. For severe cardiotoxicity, an antidote may be administered.

Peace Lily (Spathiphyllum sp.) and Calla Lily (Zantedeschia spp.)

Peace lily and calla lily are commonly mistaken for true lilies. They do not cause kidney failure like true lilies and daylilies. However, they contain insoluble calcium oxalate crystals that can be harmful if they embed into the tissues of the mouth and throat. Clinical signs include oral pain, drooling, vocal changes, and vomiting. Systemic toxicity (a harmful effect on the entire body) is not expected with these plants.

Treatment is commonly symptomatic. Treatments may include anti-vomiting support and supportive care. Prognosis is excellent. Other common insoluble calcium oxalate-containing houseplants include philodendrons, Pothos, and Dumb.

Peruvian Lily (Alstroemeria sp.)

Peruvian lilies are often mistaken for true lilies. Fortunately, exposure to these flowers is only expected to result in self-limiting stomach upset and will not cause kidney damage or other systemic disease in cats.

Sorrels and Shamrock (Oxalis sp.), Sour Star Fruit, and Rhubarb

These plants contain soluble oxalate salts. Oxalate salts are absorbed from the digestive system and bind with systemic calcium, causing hypocalcemia (abnormally low calcium levels in the blood). Calcium may accumulate in the kidneys, leading to kidney injury. Clinical signs of exposure include stomach upset and, as systemic hypocalcemia progresses, neurological and musculoskeletal signs. Acute kidney injury can develop within 72 hours.

Treatment may include decontamination, intravenous fluid therapy, calcium support, bloodwork monitoring, and other symptomatic and supportive therapies.

Tulips (Tulipa sp.)

Tulips contain toxic substances that are concentrated in the bulb but can be found in all parts of the plant. Ingestion of the leaves, stem, or flower commonly results in stomach upset. Topical exposure can result in skin irritation. More serious signs can develop if the bulbs are chewed or ingested, including cardiovascular changes. Clinical signs can develop within minutes or up to 24 hours.

Treatment may depend on the amount ingested and the clinical signs. Most cats commonly require minor symptomatic care. Large exposures or those with cardiovascular signs may require decontamination, intravenous (IV) fluids and monitoring, with symptomatic and supportive care.

True Lilies (Lilium sp.) and Daylilies (Hemerocallis sp.)

True lilies and daylilies are common in flower arrangements, especially on Valentine's Day, Mother’s Day, and Easter. While beautiful, lilies are deadly to cats. Even minor exposure to the pollen or through drinking the vase water can cause devastating illness. Toxic lilies can cause kidney failure within 6 to 48 hours of exposure.

If your cat has been exposed to these types of lilies, immediate treatment is critical. Prognosis is good if the treatment is started before the onset of kidney damage. Once kidney damage develops, recovery with aggressive treatment is possible, but the chance of survival is lower. Clinical signs typically start with vomiting and decreased appetite, which progresses to complete anorexia, lethargy, increased drinking, increased urination, and continued vomiting as kidney failure develops.

Treatment is aimed at protecting the kidneys before the onset of kidney failure. This treatment may include initial decontamination, IV fluids, blood work, and symptomatic and supportive care. Dialysis may be required in cats with severe kidney damage.

Pet Poison Helpline, an animal poison center based out of Minneapolis, MN, is available 24/7 for pet owners and veterinary professionals that require assistance treating a potentially poisoned pet. The staff provides treatment advice for poisoning cases of all species, including dogs, cats, birds, small mammals, large animals, and exotic species. As the most cost-effective option for animal poison control care, Pet Poison Helpline’s per-incident fee includes follow-up consultations for the duration of the poison case. Pet Poison Helpline is available in North America by calling 800-213-6680. Additional information can be found online at www.petpoisonhelpline.com.