Page 953 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

Poisonous Plants of the Europe Chapter | 62 905

VetBooks.ir ensues without struggle. Death occurs within approxi- TABLE 62.3 Systemic Effects of Plant Poisoning
mately 5 min. Empty right heart, dark tarry blood in left
heart, and limited nonspecific postmortem lesions such as
congestion of the kidneys, liver, spleen, and lungs are Gastrointestinal Ricinus Communis, Araceae Family
irritants
seen (Ogden, 1988). The presence of yew leaves in the
Cardiovascular Convallaria majalis, Digitalis purpurea,
rumen contents may help in making the diagnosis of yew
abnormalities Aconitum spp.
poisoning.
Renal Datura stramonium, Cicuta spp.
dysfunction
THUJA OCCIDENTALIS L. (CUPRESSACEAE Hepatic Senecio (pyrrolizidine alkaloids)
FAMILY) dysfunction

Common Name: Thuja Convulsions Cicuta spp., Coriaria myrtifolia, Aconitum,
Taxus, and Veratrum plant species
(Veratrum calcifornicum)
Thuja (Thuja occidentalis L.) shrubs are found throughout
Europe. They are frequently planted in parks and gardens Nicotine Conium maculatum
for ornamental purposes, especially in enclosures. Animal symptoms
species affected are cattle and sheep, and, rarely, goats. Atropine Datura stramonium
Poisoning occurs by consumption of branches or branches symptoms
dropped on the ground after being cut down or following
a storm.

Clinical Presentation syndromes characteristic of specific plants is of
importance.
Peracute intoxication is within a few minutes, especially
in sheep. Clinical signs of acute or subacute intoxication Many plant poisonings will not be diagnosed at the
are essentially related to the digestive tract (hypersaliva- onset of the disease. Therapy will, of necessity, be symp-
tion, colics, bloating, and bloody diarrhea) (Jean-Blain tomatic. Even when a positive diagnosis can be made,
there are rarely any specific antidotes. The most important
and Grisvard, 1973). Toxicity progresses to dyspnea and
step in therapy for any plant poisoning case is to remove
paralysis, accompanied by a cooling of the extremities.
any residual plant materials from the digestive tract as
Death can occur between 1 and 48 h depending on the
quickly as possible.
amount of plant parts ingested. The lesions are character-
Removal of unabsorbed poison from the gut can be
ized by discrete congestive gastroenteritis, which is not
achieved by several means, including induction of emesis,
specific. The presence of thuja leaves in the rumen con-
gastric lavage, and use of activated charcoal, tannins, and
tents confirms poisoning.
cathartics. Tannins and activated charcoal may be admin-
istered in water slurry via oral route.
TREATMENT In emergency medicine and for critical patients, begin
resuscitation with the airways and then breathing and cir-
Management of poisoning by toxic plants is complicated
culation in an overdose scenario. Therapeutic manage-
by the lack of antidotes to most plant toxins. However,
ment strategies can be summarized as follows:
general treatment is intended to induce emesis, reduce
establishment of a patent airway, artificial respiration,
absorption, or enhance elimination of toxin. The effect of
cardiac massage, and perhaps the application of defibrilla-
treatment may be difficult to determine because of the
tion techniques. Following stabilization of vital signs, the
wide variability in toxic reactions to the same plant.
clinician may proceed with subsequent therapeutic mea-
Table 62.3 describes some of the systemic effects of poi-
sures. Treatment involves enhancing the removal of the
sonous plants.
absorbed poison and providing supportive therapy to com-
bat the effects of the poison already absorbed.
Nonspecific Treatment
The most important aspect of emergency medicine treat- Decontamination Procedures
ment is to ensure adequate physiologic functioning. Ingestion is the most common route of poisoning in large
Treatment generally requires stabilization of vital signs. and small animals. Decisions about gastric emptying
Most plant poisoning cases respond to supportive care. depend on an accurate identification of the plant responsi-
Frequently, the veterinarian must treat the animal before ble for poisoning because the majority of casual inges-
plant identification is done. The recognition of certain tions require no specific therapy. Once identified,