Page 939 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

VetBooks.ir Chapter 62

Poisonous Plants of the Europe

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Arturo Anadon, Marı´a R. Martı´nez-Larran ˜ aga, Irma Ares and Maria A. Martı´nez

INTRODUCTION anything they encounter and are the principal candidates
for the accidental ingestion of toxic plant materials.
European flora is much less rich in dangerous species
Occasionally, a client may observe a pet consuming a
than those found in the American and African flora; how-
fruit or leafy material. A frantic call to the veterinarian
ever, the number of plant poisons is considerable.
may prove fruitless if the plant cannot be identified by
Poisoning of livestock and companion animals by plants
visual description. The amount consumed is also of
is a sporadically occurring clinical problem, and the pos-
importance. Rarely will a single bite of any plant prove to
sibility of plant poisoning is usually neglected in a differ-
be lethal. Fortunately, most plants do not cause toxicity,
ential diagnosis. In intensive rearing of animals like swine
and may only cause mild to moderate gastrointestinal irri-
or poultry, contact of the animal with the toxic plant is
tation. A few plants in certain localities, regions or coun-
unlikely. Also, the maintenance in confinement of some
tries can produce serious toxicity, including oleander
semipermanent stall dairy cattle and young beef cattle
(Nerium oleander) and castor beans (Ricinus communis).
minimizes this risk. The common use of herbicides
Household pets are exposed to the same harmful sub-
destroys some poisonous plant species. However, in many
stances as young children. Puppies and kittens, like chil-
cases, it must be determined whether animals have come
dren, seem to have a predilection to ingest attractive
in contact with toxic plants either in the pasture or by
foreign materials, such as parts of house and garden plants
means of poisonous plants mixed with forage and distrib-
(berries, fruits, seeds, leaves). Both older and immature
uted in conserved forage.
animals may suffer from boredom or behavioral abnor-
Plant poisoning in small animals is usually acciden-
malities or may simply be investigating a new addition to
tal. Accidents can be prevented by understanding the
the environment, all of which may lead to ingestion of
conditions under which poisoning may be expected to
poisonous plant material.
occur and then taking positive steps to prevent its occur-
Small pets are at greatest risk with exotic plants. They
rence. Moreover, problems can occur with animals in
are usually not herbivores, and as a result, they never
ornamental, garden and natural environments and
develop detoxification mechanisms for plants. By con-
homes. Pets are usually the victims of this type of acci-
trast, most herbivores have coevolved elaborate detoxifi-
dent. A considerable numbers of veterinarians are not
cation mechanisms to cope with the thousands of
familiar with plants found in and around the home that
alkaloids, glycosides, amines, and resinoids found in
may be potentially harmful if ingested; therefore they
plants that they typically consume. When animals and
are responsible for being prepared to deal with plant
plants evolve together, a commensal relationship often
poisoning should it occur. Many house and garden
develops. Such relations are interrupted when plants are
plants grown in Europe contain chemical substances in
introduced into new environments exposing the resident
sufficient quantities that leadtotoxic effectsinanimals.
animals to substances for which they lack detoxification
Dogs and cats are not herbivores and infrequently con-
mechanisms.
sume large quantities of plant materials. It is recog-
Finally, many poisonous substances found in plants
nized, however, that they do occasionally ingest plant
are also used medicinally. Cardioactive glycosides, atro-
materials, especially grass. When conditions are favor-
pine, and acetylcholine are three examples. Poisoning
able, both dogs and cats will consume other herbaceous
from plant material presupposes consumption of sufficient
materials that cause toxicity. Although plant poisoning
quantities of one or several active ingredients that in turn
of adult dogs and cats is unlikely, puppies often taste
Veterinary Toxicology. DOI: http://dx.doi.org/10.1016/B978-0-12-811410-0.00062-3
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