17. TOBACCO

Nicotiana spp.

(nightshade family)

TOXICITY RATING: Low to moderate, depending on the situation.

ANIMALS AFFECTED: All animals may be affected, but pets in contact with tobacco products are at risk as are pigs allowed to forage on harvested tobacco fields.

DANGEROUS PARTS OF PLANT: Leaves.

CLASS OF SIGNS: Gastrointestinal irritation, trembling, staggering, weakness, breathing problems, heart problems, collapse, birth defects, death.

PLANT DESCRIPTION: These tall annual plants grow from fibrous roots and produce large, hairy leaves and terminal clusters of tubular, 2 inches long, white, red, lavender, or yellow flowers on short stalks. Many-seeded capsules may appear in late summer. The tobacco species with colorful flowers (fig. 17) are grown as garden ornamentals. Those with yellow-green flowers and the largest leaves are an economic crop in the southern counties of the state.

SIGNS: The toxin in tobacco is nicotine, an alkaloid with an irritating effect on the stomach and intestines and also the nervous system. This toxin is related to the toxins in poison hemlock and lupine. Concerning nicotine concentrations, an average cigarette can contain between 20 and 30 mg, and 120 mg for a cigar. One report indicates that for a human unaccustomed to tobacco, 4 mg can cause clinical signs, and 60 mg at one time can cause death.

Pets can easily be poisoned by tobacco products in the home, either accidentally or maliciously. The primary route of poisoning is by ingestion (eating tobacco products or drinking tobacco-tainted water), but inhalation of smoke is also possible. Clinical signs nearly always are present, but only rarely is a lethal dose ingested. The initial signs of poisoning can develop within 10 to 15 minutes or may not manifest for several hours. At first, the irritating effect that tobacco has on the stomach and intestines will cause salivating, vomiting (if capable), and diarrhea. Shortly after the digestive signs develop, neurologic signs appear. Initially, nicotine stimulates the nervous system, with depression of the nervous system occurring at a later time. Early signs include nervousness, shaking, trembling, a stiff and uncoordinated gait, weakness and collapse. Cardiac abnormalities may be noted as well as breathing difficulties, to the point of respiratory paralysis (the cause of death in lethal cases). Tobacco is also teratogenic, causing birth defects if the mother animal was pregnant when the toxicosis occurred.

In large animals, pigs are the most likely to suffer tobacco poisoning, since they are allowed to forage on harvested tobacco fields. In addition to the gastric and neurologic signs, birth defects have been well documented when pregnant sows ingest tobacco. The most common defects are limb deformities in the piglets.

FIRST AID: For pigs and other large animals, it is unlikely that a lethal dose would be consumed. Keep the animal quiet and undisturbed and clinical signs should resolve within a few hours, although birth defects may still occur. For more severely affected large animals or in cases where it is known that a large quantity was ingested, call a veterinarian as soon as possible, since emergency evacuation of the gastrointestinal tract may be necessary. For pets, contact a veterinarian if any ingestion has occurred. With their smaller size, pets will show clinical signs more rapidly and more severely than large animals. In addition, the effects of nicotine can come on rapidly.

SAFETY IN PREPARED FEEDS: Tobacco remains toxic when dried, therefore processed feeds containing tobacco are not safe for consumption.

PREVENTION: Do not allow pets to be in contact with tobacco or tobacco products. Do not let animals drink from puddles or cups that have leached tobacco juice in them (such as when a water-filled cup has been used as an "ashtray", or spittoons), since this water can have extremely high concentrations of nicotine. Forced ingestion or inhalation is inhumane and potentially lethal. Concerning sows, there is disagreement over whether there exists a "danger window" for consumption of tobacco during gestation (currently there exists two thoughts, that on days 10 to 30 of gestation the piglets are susceptible, and another that indicates that anything after 30 days is dangerous). Until more clarity is brought to bear on the issue, do not let pregnant sows graze on tobacco.