Plants and Bengals

It is difficult to give concise information about plant toxicities as there are hundreds of plants that are potentially poisonous to animals. However, actual reports of animals getting seriously ill from eating plants are relatively infrequent compared to reports of poisonings from household products or drugs. The plants discussed below represent among the most dangerous of poisonous plants. You may notice the conspicuous lack of "holiday plants" among the list. While many people seem to think poinsettias, ivy and mistletoe are dangerous plants, and while these plants have toxic potential, they seldom cause serious clinical signs if eaten.

It is worth noting here that dogs and cats often vomit after chewing on plants; this probably does not represent "poisoning" or any dangerous exposure. Only severe or persistent vomiting is a danger sign in small animals. Sporadic vomiting without accompanying signs of illness (for instance, diarrhea, depression, loss of appetite) is rarely a cause for worry, whether associated with plant ingestion or not. The best advice, however, is to contact your veterinarian if you have specific concerns.

Christmas plants:
A number of Christmas season plants are poisonous to pets if nibbled or eaten: ivy - moderate to very toxic, all parts; holly - moderate to very toxic, especially the berries and leaves; mistletoe - very toxic, all parts, especially the berries; Christmas greens such as balsam, juniper, cedar, pine and fir - all parts have a low level of toxicity; hibiscus - may cause vomiting or bloody diarrhea if ingested; and poinsettias - leaves and stems low in toxicity. This is not a conclusive listing...there are many more toxic plants. An additional listing of both non and toxic plants can be located HERE. It's wise to keep plants out of your pet's and children's reach.

Holiday plants:
Holly and mistletoe are extremely poisonous when eaten. The lovely poinsettia may not be truly poisonous, but its milky white sap and leaves can certainly cause severe gastric distress. With so many hybrid varieties available each year, the best approach is to keep the plants out of your pet's reach. Preservatives often used in the water in a tree stand can cause gastric upsets, so be sure it is inaccessible or not used. Avoid sugar and aspirin additives in the water as well.

The ingestion of azalea, oleander, mistletoe, sago palm, Easter lily, or yew plant material, by an animal, could be fatal.

PLANTS TO BE CONCERNED ABOUT

Japenese Yew (highly dangerous)

Scientific Name: Taxus cuspidus
Common names: Yew, Spreading English Yew, Canada Yew
Plant with similar toxicity: Zygadenus nuttziii, common name Deathcamas.

The Yew plant is an ornamental yard plant, most often used in landscaping around the foundation of a house. It is an extremely poisonous plant and the animal needs to eat only one-tenth of one percent of it's body weight to get a toxic dose. (For example, a 50 pound dog would need only 0.05 pounds or less than 2 ounces of the plant to get a potentially fatal dose!) The toxin in the Yew is an alkaloid and works by depressing electrical activity in the heart. Signs may include sudden death from heart failure. If the animal shows clinical signs of toxicosis other than sudden death those could include: trembling, incoordination, diarrhea, and collapse.

We rarely recognize clinical cases of JapaneseYew poisoning in animals at the University, although that may be partly because of the difficulty in proving the presence of the toxin as well as the great toxicity. In cases where animals are found dead it is very difficult to prove the Yew caused the death unless the animal is necropsied (a veterinary term for an autopsy) and evidence of ingestion - evidence that the animal actually ate the plant - is found. There are no specific blood or chemical tests to determine if Yew toxicity is present. While Yew poisoning does not seem to be very common, the best advice is to know what ornamental plants are present around your house and other buildings and to make sure the Yew is not one of them!

Scientific name: Many, including: Schefflera actinophylla, Dieffenbachia maculata, Begonia tuberhybrida, Philodendron
Common names: Starleaf, Tuftroot, tuberous begonia, wax begonia, water plant, yellow calla, peace lily, etc.

This family of house plants and ornamentals contains oxalates and causes toxicity by the formation of calcium oxalate crystals in the animals organs and by causing the release of chemicals in the body which can cause an acute allergic reaction. Signs may include excessive salivation, head shaking, pawing at the mouth, difficult breathing, vomiting, and diarrhea. Fortunately, the plant causes pain and irritation on chewing and therefore animals rarely eat it in sufficient quantities to cause severe damage. Much of the motivation for chewing on such a plant involves boredom and other psychological factors (recent changes in the household, etc.) so it may be worth noting if an animal begins suddenly eating house plants they used to ignore and discussing the subject in a phone call or visit to your veterinarian. If your household plants include any of those in the Araceae family, be aware of the potential for toxicity and preferably keep the plants away from the pet or switch to safer house plants.

Rhododendrons (and other cardiac glycoside containing plants)

Scientific name: Many, including: Rhododendron, Nerium oleander, Digitalis purpura.
Common names: Rhododendrons, milkweeds, lily-of-the-Valley, laurel, oleander, azalea, foxglove, etc.

This group of common plants all contain cardiac glycosides. Cardiac glycoside drugs derived from one of these plants, digitalis (foxglove), have been used for many years in the treatment of heart disease in people and animals. Due to their actions on the heart, however, ingestion of plants containing glycosides can be fatal. Signs may include vomiting, diarrhea, collapse, or death from heart failure. Fortunately, the plant has a bitter and very unpleasant taste! Nonetheless, the American Association of Poison Control Centers (AAPCC) report covering 425 fatal animal poisonings in 1990 includes 4 resulting from cardiac glycoside-containing plants.

Nightshades/Solanums

Scientific name: Many, including: Solanum dulcamara, Solanum nigrum, Physalis.
Common names: Nightshades, Chinese lantern, Christmas cherry, Ornamental pepper

These primarily ornamental plants contain toxins called solanines that affect either the stomach or the brain, depending on the type of poison contained in the plant. It should be noted that some plants contain no poison whatsoever and it is impossible to be certain whether a given plant contains the poisonous substances. Clinical signs of toxicity for the plants containing the stomach poison include severe gastrointestinal upset, such as vomiting, diarrhea (possibly bloody), abdominal pain. If the toxin affecting the brain is present in the plant eaten, signs may include drowsiness, salivation, difficult breathing, trembling, weakness and collapse. The AAPCC report indicated 2 of 425 fatal poisonings occurred as a result of poisoning by solanines.

A complete listing of toxic plants can be found at our toxic plants page. It is as complete as we could compile, we make no claims that it is exhaustive.