Organic Poisons

Organic poisons overview

• many organic compounds are used around animals

  • insecticides

  • parasiticides

  • herbicides/fungicides

  • rodenticides

  • other compounds used in machinery, equipment, or the environment

• species differences in response, modified by age, gender, breed, and exposure to other drugs or compounds

Chemical stability of organic poisons

• affected by

  • storage time - loss of efficacy or increase in toxicity

  • temperature - high temps or freezing can alter compounds

• mixing with other compounds

• margin of safety

  • highly variable with compounds

  • need to follow label directions for dosing

  • may need to determine body weights rather than estimate

  • follow PPE recommendations

Solvents

• typically petroleum distillates or unique synthetics

• cause cutaneous irritation - especially if applied in excess

• examples

  • DMSO

    • penetrates skin well

    • excellent solvent

Chlorinated hydrocarbons

• commonly used as pesticides and herbicides

  • ex. DDT, chlordane, etc.

• metabolized very slowly - interferes with liver function

• excreted slowly

• stored in fat - persistence

• acute toxicity is rare - CNS stimulants

  • signs: slight twitching and tremors of muscles, hyperexcitability, hyperesthesia, loss of coordination, convulsions, death

• residue can be in food products

• no known antidotes - flush with copious amounts of cool water

Organophosphates and Carbamates

• many used as pesticides and herbicides

• action: inhibits acetylcholinesterase activity at the synaptic terminal

  • results in continuous stimulation of the nervous system

• acute toxicity is common

  • signs: excess salivation, dyspnea, abdominal pain, muscular incoordination and ataxia, convulsions, respiratory paralysis, death

  • spontaneous recovery within 2-3 hours is possible

• slow return of enzyme activity → persistent effects

• poor margin of safety

• absorbed through intact skin

Chlorinated hydrocarbons vs. organophosphates

• chlorinated hydrocarbons

  • general effects

  • slowly metabolized

  • acute signs rare

  • wide margin of safety

  • residue concerns

• organophosphates

  • nervous system effects

  • rapidly metabolized

  • acute signs common

  • narrow margin of safety

  • long-term effects

Chlorinated napthalenes

• used as lubricant and wood preservative

• responsible for X-disease (vitamin A deficiency)

  • causes hyperkeratosis in ruminants

Warfarin

• rat poison

• anticoagulant

  • Vitamin K antagonist

Ethylene glycol

• antifreeze poisoning

• severe kidney disease induced

• more of a problem in dogs and cats

Medications

• therapeutic dose of a drug may vary considerably among species

• human drugs potentially toxic to pets

  • NSAIDs

    • Ibuprofen, Acetaminophen

  • antidepressants

    • Alprazolam

  • others

    • tramadol, adderall, etc.