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[...]... 1 Toxicity Ratings Rating Class Oral LD50 in rats mg/kg Probable lethal Example dose in man 6 Super toxic less than 5 5 drops Strychnine 5 Extremely toxic 5-50 1 teaspoon Parathion 4 Very toxic 50-500 1 ounce Phenobarbital 3 Moderately toxic 500-5000 1 lb (or 1 pt) Ethanol 2 Slightly toxic 50000 -15 000 1 quart Ethanol 1 Practically Nontoxic over 15 000 over 1 quart Linseed oil Margin of Safety The LD50... veterinary toxicology and human toxicology are so closely interrelated that they are indeed inseparable DEFINITION OF A POISON It is difficult to arrive at a completely satisfactory definition of a poison A poison may be defined as any substance or matter (solid, liquid, or gaseous) which, when applied to the body outwardly, or in any way introduced into it in a very small dose, can destroy life by its... Veterinary Toxicology 19 75 The Williams and Wilkins Company, Baltimore Casarett, L.J and J Doull (eds.) Toxicology: The Basic Science of Poisons 2nd Ed Ch 3-5, 9 -12 , 14 -15 Doull, J., C.D Klaassen and M.O Amdur, (eds.) 19 80 Casarett and Doull's Toxicology: The Basic Science of Poisons 2nd ed., pp 3-27 Macmillan Publishing Company, New York Loomis, T.A (ed) 19 76, Essentials of Toxicology 2nd Ed., pp 1- 23... may be safely used on adult cattle, horses, and pigs is 0.5% Young calves and all ages of sheep and goats must not be sprayed with concentrations >0.25%; 0.5% concentrations may be lethal Adult cattle may show mild toxicity at 1% concentrations Diazinon: Young calves appear to tolerate 0.05% spray but are poisoned by 0 .1% concentrations Adult cattle may be sprayed at weekly intervals with 0 .1% concentrations... metabolizing enzymes system is also called as mixed function oxidase (MFO) enzyme system for the obvious reason that is capable of catalyzing various types of reactions The oxidase system requires the presence of a cofactor NADPH, and Veterinary Toxicology 10 molecular oxygen for its activity NADPH reduces a component of the microsomes which reacts with molecular oxygen to form an active oxygen intermediate... not enter the brain easily, so that CNS signs are mild Onset of signs after exposure is usually within hours but may be delayed for >2 days Severity and course of intoxication is influenced principally by the dosage and route of exposure In acute poisoning, the primary clinical signs may be respiratory distress and collapse followed by death due to respiratory muscle paralysis Diagnosis An important... deficient to acetylate aromatic amine groups Methylation Reactions: It is relatively uncommon form of detoxication and is confined to the heterocyclic nitrogen atoms in compound of the pyridine and quinoline type Thiocyanate Formations: Inorganic cyanides are converted by the enzymerhodanese to thiocyanate It is true detoxication, for sodium thiocyanate is nearly 200 times less toxic than sodium cyanide and... Chemical Nature The physical state, e.g., whether solid, powder, orin solution will affect the dose of a poison Coarsely crystalline arsenic trioxideis slowly absorbed and so has relatively low toxicity; finely powdered arsenic is highly toxic Many substances are readily absorbed from oily than from aqueous solution, e.g., insecticides Chemical nature is important in ;egard to toxicity, yellow phosphorus... process Physical Action: Because of their physical properties such as lipid solubility, some substances exert a non-specific inhibitory effect on enzyme systems by virtue of the fact that their physical nature is such as to bring about their accumulation in vital parts of cells where they depress cellular functions Many compounds, including hypnoti~s and anesthetics such as hydrocarbons, chlorinated hydrocarbons,... forages previously sprayed with this insecticide Fenthion: Minimum toxic dose, PO, is 25 mg/kg body wt for cattle; 50 mg/kg is lethal to sheep Malathion: Malathion is one of the safest organophosphates Young calves tolerate 0.5% but not 1% sprays; adult cattle tolerate 2% sprays Given PO, it is toxic at 10 0 mg/kg but not 55 mg/kg body wt; young calves tolerate 11 mglkg but are poisoned by 22 mglkg Malathion . ISBN: 978-93-8 017 9-28-5 Edition 2 010 Oxford Book Company 267, 10 -B-Scheme, Opp. Narayan Niwas, Gopalpura By Pass Road, Jaipur-302 018 Phone: 014 1-2594705, Fax: 014 1-2597527 e-mail:. Strychnine 5 Extremely toxic 5-50 1 teaspoon Parathion 4 Very toxic 50-500 1 ounce Phenobarbital 3 Moderately toxic 500-5000 1 lb (or 1 pt) Ethanol 2 Slightly toxic 50000 -15 000 1 quart. Drugs 95 -12 2 6. Food Poisoning 12 3 -13 2 7. Poisonous Plants 13 3 -17 4 8. Industrial Poisoning 17 5-208 9. Biotoxins 209-228 10 . Endocrine To~icology 229-276 Bibliography 277-278