by Guy R. Hodge, HSUS Director of Research and Data Services
In our woods and fields, even in our homes and gardens, plants provide a special beauty and sense of nature. While plants add a touch of color and fragrance to our daily lives they also inject an element of danger into the lives of our pets. More than 700 plants have been identified as producing physiologically active or toxic substances in sufficient amounts to cause harmful effects in animals. Poisonous plants produce a variety of toxic substances and cause animal reactions- ranging from mild nausea to death. Certain animal species may have a peculiar vulnerability to a potentially poisonous plant.
More than 300,000 species and subspecies of plants have been identified by botanists. Relatively few plants have been tested or studied for toxic properties. On the following page there is a list of some of the common plants which may produce a toxic reaction in animals. There is a difference of opinion among scientists with regard to the poisonous properties of individual plant species. The HSUS list is intended only as a guide to plants which are generally identified as having the capability for producing a toxic reaction.
If you are uncertain about the poisonous properties of a particular plant, contact your veterinarian or agricultural extension service office or consult Walter Muenscher's Poisonous Plants of the United States (Collier Books, 1975). In evaluating the toxic properties of plants which you are considering for home or garden do not rely upon the opinions of store clerks or hobby gardeners. Several so-termed "harmless" plants may form toxic products when decomposed or they may produce a poisonous substance as a result of interaction with a microorganism such as fungi. Several plants cause poisoning only during certain seasons of the year and other plants produce toxic agents only during particular stages of development.
At least five distinct physiological reactions are caused by poisonous plants. Accordingly, the toxic properties of plants have been classified as blood poisons, neurotic poisons, neuromuscular poisons, muscular poisons, and irritants, Symptoms of poisoning in animals include trembling, cramps, fever-, panting, vomiting, diarrhea, hives, convulsions, and rigid extension of the neck and limbs.
First aid treatment depends upon the type of poison ingested. If possible, a veterinarian should be consulted before initiating emergency treatment. A majority of the cases of plant poisoning in animals are caused by the toxic substance entering through the animal's digestive tract. If the animal has been observed consuming a poisonous plant it may be beneficial to induce immediate vomiting by administering a strong salt solution consisting of six teaspoons of salt to a glass of water. As an alternative prescription you may use mustard mixed with water or several teaspoons of salt placed directly on the back of the animal's tongue. To be effective first aid treatment must be administered prior to absorption of the poison into the gastrointestinal tract. After vomiting has been induced give the animal egg whites or milk.
It is imperative that a veterinarian be consulted whenever an animal is suspected of having ingested a toxic substance. An animal which exhibits any of the symptoms associated with poisoning should be rushed to a veterinary, clinic. If a veterinarian is unavailable, consult an MD for assistance. It is helpful if you can identify the plant which your animal consumed. Veterinary treatment will also be assisted if you can inform your veterinarian of the approximate quantity of poison consumed. Remember plant poisoning is a Medical emergency. First aid treatment is intended only to minimize the effect of the poison and delay the onset of symptoms which would complicate veterinary treatment. To assure the successful and complete recovery of a poisoned net the animal should receive immediate veterinary treatment. See the list of poisonous plants.