Don’t Eat That! Poisonous Plants for Pets
By Dr. Rachel Duncan, Veterinarian
Do you ever catch your dog chewing on the plants in the yard or cat grazing on the greenery? Many pets are occasionally interested in eating plants they encounter. Luckily, most typical house or yard plants are non-toxic when ingested in small quantities or only cause minor gastrointestinal upset. However, there are several poisonous plants of which every pet owner should be aware.
Oral irritants (oxalate-containing plants)
Some plants have crystals (insoluble oxalates) that cause an immediate response upon ingestion. These plants include common house and office plants of the Diffenbachia and Philodendron families. Ingestion of these plants often causes a dramatic response because of significant oral irritation from these sharp crystals. The most frequent symptoms are profuse salivation, pawing at the mouth, retching or vomiting, and possible swelling in the mouth. These signs are dramatic but are generally limited to the mouth and quickly resolve. Rinsing the mouth, offering small amounts of milk or yogurt, and monitoring for resolution are frequently all that is necessary. If signs aren’t resolving or there are any questions regarding type of plant ingested, please contact your veterinarian for assistance.
As warm weather approaches, lilies become a popular flower in bouquets and arrangements. Be careful if your family contains any felines! Any true Lily (Lilium and Hemerocallis spp.) is extremely toxic to cats. These plants include Easter lilies, tiger lilies, rubrum or Japenese showy lilies and various day lilies. Ingestion of any part of the plant, in even very small quantities, can result in kidney failure. Drinking water from the vase or ingesting pollen is also believed to be toxic. Dogs are not susceptible to this toxicity. If you believe your cat may have ingested any part of a lily plant, please seek a veterinarian immediately for assistance.
With spring planting here, be aware that some spring bulbs are toxic when ingested. These flowers include tulips and hyacinths (Lilaceae family), and daffodils (Narcissus spp). The toxic component of these plants is contained in the bulb. Toxicity often occurs when a curious dog digs up freshly planted bulbs or ingests bulbs waiting to be planted. Ingestion may cause gastrointestinal upset and excessive salivation. Elevated heart rate, changes in breathing and neurologic signs may result at higher doses. Symptomatic and supportive care provided by a veterinarian is recommended.
Plants Toxic to the Heart
Several types of plants contain naturally occurring chemicals that can cause severe abnormalities to heart function, including possible death. These chemicals are similar to digitalis or digoxin, which is used therapeutically in human and veterinary medicine. These plants include foxglove (Digitalis lannate, D. purpuea), oleander (Nerium oleander), star of Bethlehem (Ornithogalum umbellatum), milkweed (Asclepias spp.), lily of the Valley (Convallaria majalis), Kalanchoe (Kalanchoe spp.) and dogbane (Apocynum cannabinum). The toxicity ranges depending on type of plant, and amounts and parts consumed, but is considered very high. Symptoms of toxicity include gastrointestinal upset, cardiac abnormalities (arrhythmias, death), and neurologic disease. Treatment of any suspected toxicity should be performed under the care of a veterinarian.
Sago, or cycad, palms are natural to tropical and subtropical environments but are also commonly used as indoor plants. These plants include Cycasi, Zamias and Macrozamia spp such as cycads, Japanese cycad/palm, coontie plant and cardboard palm. All parts of these palms are toxic to dogs. The most concentrated amount of the toxin, cycasin, is contained within the seeds. Toxicity includes gastrointestinal upset, neurologic disease and liver failure. Treatment should be sought immediately if ingestion is suspected, as aggressive management early ensures the best outcome.
While most plant ingestions have only minor or no effects, some may cause significant disease. Several other poisonous plants may be encountered that are not listed here. The ASPCA sponsors toxic and non-toxic plant galleries at their website for plant identification and further information. The ASPCA Animal Poison Control Center (888-426-4435) is also a recommended resource for obtaining the most accurate and current veterinary-specific clinical advice. Your veterinarian should also be contacted immediately if you have any questions regarding possible poisoning.
Please enjoy the beauty of plants and flowers safely with your pets!