VPT 421: Veterinary Toxicology (2+0)

CONIUM MACULATUM
(Hemlock)

This plant can be easily identified by the distinct mouse like odour emitted by all parts of the plant when crushed or bruised. This plant contains many alkaloids of which coniine is the most important alkaloid. Coniine produces nicotine like action in first-stimulating and then depressing the autonomic ganglia. It also has curare like actions in paralyzing the motor nerve endplates of skeletal muscles. The clinical symptoms include, papillary dilatation, weakness and a staggering gait, initially the pulse is low and later it becomes rapid and thready, respiration becomes slow, laboured and irregular and respiration is arrested before the heart beat stops. Consciousness is not usually lost. The alkaloid is excreted from the body through lungs and kidneys. Hence the exhaled air and urine have peculiar mouse-like smell. The plant can produce teratogenic effects. The post-mortem changes are not characteristic. Treatment should be aimed at removing the source, emptying the stomach contents, administering purgatives and tannic acid to neutralize the alkaloid. Stimulants are also found to be useful.