Poisons

Flashcards covering common veterinary poisons, clinical signs, mechanisms of action, and emergency first aid and treatment protocols.

Poison

A substance that, upon entry into the body in sufficient amounts, produces a harmful effect; exposure can occur via ingestion, skin absorption, or inhalation.

Principles of Poison Treatment

The core protocol for handling poisoning cases: prevent further absorption, identify the poison if possible, contact the Veterinary Poisons Information Service (VPIS), treat symptoms, and administer an antidote.

Renal Recirculation of Toxins

The physiological process where $75\%$ of blood reaching the kidney is recirculated into the bloodstream via the renal tubule system, which can cause fatal and irreversible kidney damage when filtered toxins re-enter circulation.

Emetics

Substances used to induce vomiting when a non-corrosive poison has been ingested within the last $30\text{ minutes}$ to $1\text{ hour}$; methods include two teaspoons of mustard in warm water, two pea-sized crystals of washing soda on the back of the tongue, apomorphine, or xylazine/medetomidine (salt solutions are no longer advised).

Contraindications for Inducing Vomiting

Circumstances under which emesis must NOT be induced: if the ingested poison is corrosive (e.g., petrol, creosote), if the patient is unconscious or fitting, or if ingestion occurred more than $4\text{ hours}$ prior.

Gastric Lavage

A veterinary procedure performed under general anaesthesia (GA) to wash ingested substances from the stomach using warm water or saline introduced repeatedly via a stomach tube, often followed by activated charcoal administration.

Activated Charcoal

An oral agent administered to bind and absorb remaining toxic contents within the gastrointestinal tract, preventing their systemic absorption.

Saline Purge

A treatment used to accelerate the passage of substances through the gastrointestinal tract; it is contraindicated if the patient is in shock or if the digestive tract is inflamed.

Demulcents

Soothing agents that relieve irritation of mucous membranes by coating the lining of the digestive tract with a protective film; examples include arrowroot, glycerin, bismuth carbonate, or raw egg beaten with milk and honey or sugar.

Decontamination of Non-Oily Liquids

First aid for external coat contamination with non-oily liquids (such as disinfectants) involving copious rinsing with water while avoiding detergents, which can make the substance fat-soluble and increase skin absorption.

Decontamination of Oily Liquids

First aid for external coat contamination with oily substances (such as engine oil or creosote) by applying Swarfega, Fairy Liquid, liquid paraffin, or cooking oil worked thoroughly into the coat, followed by washing in warm water and detergent.

Decontamination of Solid Coat Contaminants

Management of dried paint or tar on an animal's coat by clipping away the affected hair and applying a buster collar or protective clothing to prevent the animal from grooming or interfering with the site.

NSAID Toxicity (Ibuprofen)

Poisoning with a narrow safety margin characterized by acute gastrointestinal signs, renal failure, seizures, or coma; toxic doses causing GI signs are $>50\,\text{mg/kg}$ in cats and $>100\,\text{mg/kg}$ in dogs, with renal signs occurring at $>300\,\text{mg/kg}$.

Warfarin (Rodenticide)

An anticoagulant rodenticide that can take several days to produce clinical signs of haemorrhage; treatment includes emesis, activated charcoal, Vitamin K, and whole blood or plasma transfusions.

Theobromine Toxicity

Chocolate toxicity in dogs resulting from their inability to digest theobromine; toxic doses range from $100-150\,\text{mg/kg}$, impacting the heart, central nervous system, and kidneys, with symptoms appearing $4-24\text{ hours}$ post-ingestion.

Paracetamol Toxicity

Toxicity caused by ingestion of paracetamol ($50-100\,\text{mg/kg}$ in cats; $>100\,\text{mg/kg}$ in dogs) manifesting as cyanotic mucous membranes, respiratory difficulties, facial swelling (notable in cats), or liver failure (in dogs); treated with emesis, oral ascorbic acid, and cimetidine.

Permethrin Toxicity

Poisoning commonly occurring from over-the-counter flea treatments that is highly toxic to cats even in small quantities; clinical signs include twitching, muscle tremors, and seizures, requiring sedation, general anaesthesia, and intensive nursing care.

Metaldehyde Toxicity

Poisoning from slug bait ingestion with toxic doses of $210-600\,\text{mg/kg}$ in dogs and $207\,\text{mg/kg}$ in cats; causes seizures, depression, lethargy, vomiting, diarrhoea, and metabolic acidosis; treated by gastric lavage, activated charcoal, cooling, and seizure control.

Paraquat Toxicity

Weed killer toxicity occurring at $25-50\,\text{mg/kg}$ that causes vomiting, dyspnoea, and renal and hepatic impairment; managed exclusively with symptomatic care.

Ethylene Glycol Toxicity

Antifreeze poisoning that leads to irreversible kidney failure within hours; initial signs include depression, ataxia ('drunken' gait), greenish-blue vomitus, PUPD, and seizures, with delayed signs developing in $1-3\text{ days}$.

Lily Toxicity

Plant intoxication specific to cats causing acute renal failure; managed symptomatically.

Grape and Raisin Toxicity

Ingestion of grapes, raisins, currants, or sultanas where any amount can be toxic to dogs, causing vomiting, diarrhoea, and kidney failure.

Adder Bites

Envenomation by the UK's native venomous snake occurring in warmer weather, commonly affecting limbs or muzzle; presents with rapid swelling, puncture wounds, depression, shock, or anaphylaxis; treated with wound care, shock management, antihistamines, IVFT, and antivenom.