Devil's-backbone
General poisoning notes:
Devil''s-backbone (Kalanchoe daigremontiana) is an indoor ornamental plant. This plant contains a cardiac glycoside that has caused experimental toxicity and death in chicks and mice. It has caused illness in pets, such as rabbits and mice. Dogs and cats are also at risk from ingesting plant material. The plants should be kept away from children, as well. Devil''s-backbone produces plantlets along the leaf margins, which fall off and become new plants. These plantlets can be found in profusion around the pot in which an adult devil''s-backbone is growing. Children and family pets have easy access to these plantlets. Several other species of Kalanchoe may be found growing as houseplants in Canada. Tests have shown that some of them may also contain toxic bufadienalide compounds. These compounds were only recently discovered (Williams and Smith 1985, Joubert 1989), and so caution should be exercized with all species. Some members of the genus Kalanchoe have caused poisoning of sheep and cattle in South Africa and Australia, where they are native or naturalized (Cheeke and Schull 1985, Williams and Smith 1985).
Nomenclature:
Scientific Name: Kalanchoe daigremontiana Hamet & Perr.
Vernacular name(s): Devil's-backbone
Scientific family name: Crassulaceae
Vernacular family name: orpine
Kalanchoe daigremontiana Hamet & Perr.
Geographic Information
Plant or plant parts used in or around the home.
Notes on Poisonous plant parts:
Williams and Smith (1984) found that the leaves contained more toxin than the stems.
Toxic parts:
Leaves, stems
Notes on Toxic plant chemicals:
Daigremontianin is a bufadienolide. Bufadienolides are cardiac glycosides that are similar to cardenolides, differing only in the structure of the C-17 substituent on the D ring. This chemical has been found to be toxic in experiments on mice (Wagner et al. 1985).
Toxic plant chemicals:
daigremontianin
Daigremontianin
Animals/Human Poisoning:
Note: When an animal is listed without additional information, the literature (as of 1993) contained no detailed explanation.
Cats
General symptoms of poisoning:
Breathing, labored, convulsions, paralysis.
Chickens
General symptoms of poisoning:
Breathing, labored, convulsions, death, depression, incoordination, muscle twitching, paralysis, trembling.
Notes on poisoning:
Experimental feeding of leaf extracts to chicks caused depression, closed eyes, ruffled and drooping feathers, twitching of the neck and head, and often spiralling of the head over the back. In severe cases, convulsions, paralysis, neck and limb tremors, and death occurred. A dosage of 8 mg/g of body weight caused mild symptoms; dosages between 12-20 mg/g of body weight caused some deaths. Stem extracts produced less severe symptoms and no deaths, even when fed at the equivalent of 20 mg/g of body weight (Williams and Smith 1984).
Rabbits
General symptoms of poisoning:
Breathing, rapid, opisthotonos, paralysis.
Notes on poisoning:
A pet rabbit ate three-quarters of a leaf and became depressed and torpid; it subsequently experienced rapid breathing and teeth grinding. It fell down when attempting to walk. Paralysis followed. An injection of atropine was administered, and the rabbit recovered fully within 9 h (Williams and Smith 1984).
Rodents
General symptoms of poisoning:
Muscle spasms, paralysis.
Notes on poisoning:
In motility tests, mice experimentally fed the chemical daigremontianin at dosages of 0.1-0.5 mg/kg experienced a strong sedative effect. Higher concentrations resulted in paralysis and spasmodic muscular contractions (Wagner et al. 1985).
