This column is the second in a series with information about plants toxic to dogs, cats and horses.
In my last column, I discussed plants that contained calcium oxalates. This time I will cover plants with various saponins as the toxic component. Again, most animals will avoid these plants, but some hardheads can’t resist.
Animals that ingest the fruits of these plants, usually berries, will demonstrate signs of gastric upset, vomiting, abdominal pain and diarrhea. Some animals may rub against these plants and will develop, with repeated skin exposure, an allergic dermatitis.
As always, if you believe your pet interacted with one of these plants, please take it to your veterinarian and explain the circumstances.
Plants from the Asparagus family contain sapogenins. Included in this family are Asparagus, Asparagus Fern, Emerald Feather, Emerald Fern, Plumosa Fern, Lace Fern, Racemose, and Shatavari.
Various Holly plants contain saponins including; the American Holly, the English Holly, the European Holly, Oregon Holly, Inkberry, Winterberry and Spanish Thyme. Both the leaves and berries of these plants are toxic and ingestion can result in gastric upset.
Aloe (Aloe vera) plants contain saponins and ingestion can result in gastric upset, anorexia (loss of appetite), tremors and, at times, a change in urine color. Ingestion of the Baby Doll Ti Plant, also known as the Ti-Plant, Good-Luck Plant and Hawaiian Ti Plant, can result in vomiting, sometimes containing blood, depression, anorexia, hypersalivation and, in cats, dilated pupils. Ingestion of Buckeyes or Horse Chestnuts can result in severe vomiting and diarrhea, either depression or excitement, dilated pupils and, in severe cases, wobbly gait, convulsions and even coma. Cyclamen (Sowbread) contains terpenoid saponins and eating this plant will result in gastric upset. Ingestion of large quantities of the tubers of this plant can result in abnormal heart rhythm, seizures and even death.
The foliage of the English Ivy (Branching Ivy, Glacier Ivy, Needlepoint Ivy, Sweetheart Ivy, California Ivy) is more toxic than the berries. Ingestion of the leaves will result in gastric upset. The toxic substance in these plants are triterpenoid saponins.
Dracaena, also known as Corn Plant, Cornstalk Plant, Dragon Tree and Ribbon Plant, are toxic when ingested. Ingestion can result in gastric upset severe enough to have blood in the vomitus. Contact with the Coffee Tree (Wild Coffee, Geranium-Leaf Aralia) can result in dermatitis, ingestion with gastric upset and depression. If your dog or cat ingests portions of the Yucca it may develop gastric upset. Interestingly, grazing animals — horses, cattle and sheep — can develop liver disease and secondary photosensitivity if they eat enough of the Yucca. Unless severe drought conditions exist, grazers will avoid these plants. The Hosta (Plantain Lily, Funkia) is included in those plants with saponins and ingestion can result in gastric upset.
The specific toxic substance in the Bird of Paradise (Peacock Flower, Barbados Pride, Poinciana, Pride of Barbados, Dwarf Poinciana) has not been identified but ingestion of this plant can result in intense oral irritation resulting in hypersalivation, vomiting, diarrhea, difficulty swallowing and, in severe cases, incoordination. Rabbits eating this plant have died. The Buttercup (Butter Cress, Figwort) contains the irritant protoanemonin and ingestion can result in gastric upset and a wobbly gait. The many varieties of Chrysanthemums can contain sesquiterpene, lactones, pyrethrins and other irritants and can result in gastric upset. Pinks (Carnations, Wild Carnation, Sweet William) contain an unknown irritant that can cause mild gastric upset.
Two plants, the Poinsettia and the Pencil Cactus, are often identified as toxic. The Poinsettia is especially bad-mouthed around Christmas time, but the toxicity of these plants is generally overrated, their sap is a mild irritant.
The truly dangerous plant, a favorite of mystery writers, is the Black Nightshade (Nightshade, Deadly Nightshade). This plant, Solanum nigrum, contains saponins but also contains solanine, and atropine-like substances. Ingestion can result in hypersalivation, loss of appetite, severe GI upset, diarrhea, drowsiness, depression of the central nervous system, confusion, behavioral changes, weakness, severely dilated pupils and a very slow heart rate. Your pet would have to ingest a lot of this plant to cause death and because the toxic components are so much of an irritant, this usually will not happen.
Dr. David Gross of Edmonds graduated from Colorado State University’s veterinary school in 1960 and was in private practice for 10 years. He retired in 2006 as Professor and Head of Veterinary Biosciences, at the University of Illinois, Urbana-Champaign. Dr. Gross is the author of “Animals Don’t Blush,” which describes the unique patients and even more unique clients of a veterinary practice in Sidney, Montana in the early 1960s. He will be signing copies of his latest book, “Manhunt,” about a true crime family, from noon to 1 p.m. at the Edmonds Bookshop on Saturday, Nov. 3.