Natural toxins: Part 2 (Proceedings)
A lingering human impression that most synthetic chemicals/compounds are unsafe and those of natural origin are safe remains un-substantiated. Of an estimated 30,000 plant species (wild and cultivated) found in North America, approximately 700 species have been reported toxic to animals. These plants are toxic on account of chemicals found in them, which are toxic to animals on ingestions. These components (alkaloids, glycosides, phenols, phyto estrogens, resins etc.) are structurally and functionally diverse. Components of both Mushrooms and Fungi are equally diverse and cause toxicity in animals on ingestion. Veterinarians by training are not botanist but could be benefitted working with botanist (Taxonomist) in specimen Identifications.
This presentation discusses secondary metabolites (toxins) found in some plants, mushrooms and fungi which are reported toxic to pets. The young of the species seems more susceptible – curiosity. Treatment in most cases is at best symptomatic and supportive.
Sudden weakness and inco-ordination in animals following ingestion of some plant are suggestive of insult to either to the cardiovascular, nervous of musculoskeletal system,Weakness and inco-ordination are suggestive of insults to either the cardiovascular, nervous or musculoskeletal system. Enzymes PK and LDH isozymes would be helpful in narrowing the differential.
Digitalis purpurea, Nerium oleander, convallaria majalis contain cardioglycocides compounds known to increase the force and contraction of the myocardium. In addition, such compounds cause cardiac blockage., Cardiac glycosides, by inhibiting the Na-K-Na K ATPase pump. This requires emergency treatment. Cardiac glycosides are found throughout the freshly cut and/or portions of the plants.
Convallaria majalis "Lily-of-the-Valley"
A perennial herb with slender running rootstock and leafless stem. Raceme of white bellshaped flowers. Fruits often ripen into red berries (seldom formed), a common flower garden plant, seldom eaten. Toxicity occasionally reported in Dogs,
Nerium oleander "Oleander"
An ornamental shrub of small densely branched tree. Leaves opposite or whorled, leathery, evergreen, elliptic with entire margin. Flowers are in terminal cluster, white, pink, red or yellow in color. All species including man are affected Very potent glycosides - 0.005-0.015% body weight causes death of animal.
Clinical signs: Severe gastroenteritis, increased pulse rate, bloody feces, vomiting, diarrhea, mydriasis, cardiac stimulation initially, followed by cardiac depression, coma and death (weakness, cold extremities).
Ricinus communis "castor-oil plant, castor bean, steadfast, wonder tree."
A large, robust annual or perennial woody herb with alternate, simple-palmately, lobed (7-9) and serrated leaves. Pungent odor when handled. Flowers are green and inconspicuous. The fruit is a three-lobed capsule with spiny exterior (three seeds per capsule). The seeds are large and mottled, usually a light brown (resembling engorged ticks).
Cannabis sativa "Mary Jane, Marijuana, Grass, Pot, Hashish, Indian hemp"
A course rough stemmed annual plant, formally cultivated for its fiber, is now widely used for medicinal and recreational purposes. It contains the mine altering compound tetrahydrocannabinol (THC) and closely related compounds, which affects all animal species including man. Pets are exposed by ingesting marijuana cigarette butts, human cancer medication, and/or marijuana prepared confectionaries.
Highly lipophilic, readily absorbed from the GI and respiratory paths. Slow in eliminating from the body – sequestered in body fat and undergoes entero-hepatic re-circulation.