35. HEMP, MARIJUANA, HASHISH, HASH

Cannabis sativa

(nettle family)

TOXICITY RATING: Low. Animals tend to avoid this plant, and toxic encounters are rarely fatal.

ANIMALS AFFECTED: All animals, pets as well as horses and livestock, may be affected.

DANGEROUS PARTS OF PLANT: Leaves, stems, flowers, seeds.

CLASS OF SIGNS: Behavioral changes, trembling, incoordination, gastrointestinal signs, sometime breathing difficulty.

PLANT DESCRIPTION: This coarse, roughly hairy, herbaceous annual, at least 3 to 6 feet tall, has opposite leaves on the lower part of the plant, alternate leaves above (fig. 35). The leaves are made up of from 3 to 7 coarsely-saw-toothed, rough-to-the-touch, long, narrow leaflets borne in a finger-like arrangement. Male and female flowers are found on separate plants, the male flowers on branch tips and the female along the length of the branches. Hemp may be found in weedy pastures, fence rows, brushy stream banks, and illicit plantings.

SIGNS: Nearly all animals will voluntarily avoid marijuana. Toxic cases are usually encountered when the plant is mixed in prepared feeds or bedding materials, or if the animal is forced into consuming or inhaling smoke from the plant. Signs can include nervousness and disorientation which can progress to depression, trembling, vomiting (in those species that can vomit), and sometimes diarrhea and breathing difficulties. Fatalities are rare. Animals more likely to be poisoned are pets (especially dogs and birds), and perhaps swine, but all species are susceptible.

The primary toxic component is tetrahydrocannabinol, a resin. In addition, alkaloids and glycosides are present in marijuana. Toxicity varies greatly in the plants. The top leaves and flower buds of the female plants contain the highest toxin concentration, with the rest of the plant as well as male plants being toxic to a lesser degree.

FIRST AID: In nearly all cases, effects will wear off within a few hours with little or no permanent damage done. In cases of massive (or malicious) poisoning, contact a veterinarian as soon as possible. Emergency evacuation of the gastrointestinal tract may be necessary with followup supportive care. In cases where an animal (most often a dog) has consumed marijuana in baked goods (typically brownies), chocolate toxicosis may be additive to marijuana toxicosis. A veterinarian needs to be contacted in both cases of toxicoses.

SAFETY IN PREPARED FEEDS: Marijuana remains toxic when dried, therefore prepared feeds will still be toxic.

PREVENTION: Do not allow animals to have contact with the plant or any "preparations" where it might be contained and do not allow malicious intoxication.