Veterinary Taxicology

EXPOSURE RELATED FACTORS

• Dose – Low levels of many toxic agents will have no effect, intermediate and repeated doses may produce either no effect or chronic poisoning, and higher levels may produce either subacute or acute intoxication.

• Prior exposure – Prior exposure of individuals to non-toxic levels of a poison can result in the development of a tolerance to its action. This effect is seen with nicotine in smokers, morphine in drug addicts and the anticoagulant warfarin in rats.
• Route of exposure – Route of entry of a poison plays a major role in modifying the toxic effects. In general, toxic effects are more when a toxicant enters through inhalation or intravenous route.