Page 944 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

896 SECTION | XIV Poisonous Plants

VetBooks.ir AMIANTHIUM MUSCAETOXICUM in flower beds, or in pots within homes or vacant lots.
Marijuana is the term used to describe the dried leaves
(LILIACEAE FAMILY)
and flowering heads of the cannabis plant.
Common Names: Fly Poison, Stagger Grass,
and Crow Poison
Active Principle
This Amianthium muscaetoxicum plant is found in open
The main psychoactive ingredient in the plant is the com-
woods, fence rows, old fields, roadsides, and pinelands,
plex chemical delta-9-tetrahydrocannabinol (THC). This
particularly in clay soils, although it can also be found in
accounts for 3% 4% of the dry weight of the herbal
sandy soils. These plants are perennial, subscapose, and
material, although modern strains of the plant grown
bulbous herbs. Leaves are mostly basal and linear. Flowers
indoors under intensive cultivation conditions may con-
are white, turning greenish in age; they are borne in dense
tain as much as 15% 20%. The pharmacological effect
racemes. Plants are found mostly in moist, wooded slopes,
of this agent is to produce central nervous system (CNS)
meadows, open fields, and bogs.
depression and derangement. THC is absorbed when
taken by mouth, having a low oral bioavailability result-
Toxicity
ing from a large first-pass effect because of extensive
The highest concentration of the toxin, an alkaloid, is liver metabolism (taking as long as 3 or 4 h to reach peak
found in the bulb of the plant. The alkaloid is also found blood levels).
in the fruit and leaves. Animals consume the plant only
when other forage is unavailable. Cases of toxicity occur
in the spring, summer, and fall. Cattle and sheep are most Conditions of Poisoning
commonly affected.
The quantity of the active ingredient exposed varies
markedly according to the variety of the plant, the sex of
Clinical Presentation the plant, the geographical location (pasture, woods, dry
Animals exhibit vomiting, frothing at the mouth, saliva- lot, near river or pond, confined indoors), the stage of
tion, staggering, dyspnea, subnormal temperature, and growth, and the nature of the growing season. The great-
weakness. Death is caused by respiratory failure. est concentration of the active ingredient is in the flower-
ing tops of the female plant, whereas leaves are less
potent and seeds contain little of the active ingredient
(Osweiler, 2011).
CANNABIS SATIVA Individuals involved in the use of illicit drugs fre-
(CANNABINACEAE FAMILY) quently keep pets that have access to the plants, or to pro-
ducts made from the plants, and this can potentially cause
Common Names: Marijuana, Marihuana, marijuana poisoning. Some individuals delight in involv-
Bhang, Hashish, Ganja, and Sinsemilla ing their pets in the drug experience with them. In other
cases, accidental ingestion results in toxicity to the pet.
The term marijuana refers to the dried leaves and flowers
of the Indian hemp plant, which is cultivated illicitly for
its psychological effects. It is an illicit drug plant and its
leaves, flowers, and seeds contain several cannabinoids Clinical Presentation
that are favored by some people for their psychoactive Clinical signs seen in man with high doses of marijuana
properties. Originally, the plant Cannabis sativa was an include hallucinations and strange fantasies, and the user
annual herb that was native to Asia, but it has spread can no longer hold a coherent conversation. There is com-
throughout the world. Marijuana hemp both come from monly a sudden stimulation of appetite, particularly for
the same cannabis species, but are genetically distinct and sweet foods. These effects may be followed by tiredness
are further distinguished by use, chemical makeup, and and sleep.
cultivation methods; have been employed for thousands Animals show behavioral abnormalities and hyperex-
of years as a source of fiber to make rope in Asia and in citability. The animal most affected is the dog. The main
the Middle East as a medicinal and recreational drug. clinical signs in the poisoned dog are vomiting, salivation,
Only since the 1960s and 1970s has the recreational use incoordination, alternating somnolence and hyperactivity,
of marijuana become common in the Eastern world. It is muscular weakness, and hyperthermia. Moreover, CNS
currently sold in the illicit drug trade and can be found and respiratory depression is another important sign in the
growing in European countries in out-of-the-way places, dog. This is followed by coma and possibly death.