Small animal Toxicology Flashcards
What are the routes of intoxication?
*Oral - most common
*Cutaneous / topical
*Inhalation
*Injection
*Ocular
What are the steps to do when a patient comes in?
- Stabilise the patient - resp, CV, CNS signs, thermoregulation
- Obtain a complete history -toxin, time + amount ingested
- Decrease absorbed dose - emesis, lavage
What is the aim of decreasing absorbed dose?
*Prevent further absorption
*Increase elimination
*Bind toxin in inert form
How is the toxin dose decreased?
*Emesis - apomorphine in dogs
-Xylazine / dexmedetomidine in cats
*Gastric lavage
*Adsorbents
When should emesis be performed?
*Within 3hr of ingestion
-can be up to 6hr for aspirin +12hr for chocolate
What are contraindications for emesis?
– animal has been vomiting
– absent gag reflex
– sedation or loss of consciousness
– seizuring
– Ingestion of corrosive substance or volatile petroleum based product
What can be used to reverse apomorphine?
Naloxone - doesn’t stop the vomiting
When would you use gastric lavage?
When cannot induce emesis
-must have ET tube in place
-repeat lavage 10-15 times until lavage clear
What is an example of an adsorbent?
Activated charcoal
What can be used to enhance toxin clearance?
*Cathartics - sorbitol
*Enema
*Diuresis
What are examples of cathartics?
*Sorbitol
*Sodium / magneisum sulphate
*Liquid paraffin
What can be used to prevent hypothermia?
*Blankets
*Heat pads
What is used to prevent hyperthermia?
*Cold packs - luke warm to cool water - not cold/ice
*Careful not to over cool
What drug is a respiratory stimulant?
Doxapram
What can be used as Cardiovascular support?
*IVFT - crystalloids, colloids, blood
*Arterial blood pressure
*Electrolytes
What analgesia should be given in toxin ingestion?
*Opioid - pethidine (short duration)
-buprenorphine (partial agonist)
What should be done if animal is in depression / coma?
- Ventilatory support (manual/mechanical ventilation)
- Keep warm
- Maintain fluid and electrolyte balance
What should be done if animal in hyperactivity / seizuring?
*Diazepam - antiepileptic
*Phenobarbital - antiepileptic
*Propofol
When would you not use diazepam / phenobarbital?
When toxicity of the liver
What can be used for samples in toxic animals?
*Heparinised blood
*Urine
What lilies are toxic to cats?
*Easter lily
*Tiger lily
*Day lily
What can pyrethrins cause in cats?
- Excessive salivation
*tremors
*ataxia
*depression
*hyperthermia/hypothermia
What can be used to treat pyrethrin toxicity in cats?
*Bathing
*Emesis
*Activated charcoal
*Diazepam
*Methocarbamol
What does paracetamol ingestion cause in cats?
*Oxidative injury to RBCs
*Hepatotoxic 24hrs post ingestion
*Vomiting, abdominal pain, tachycardia, pallor, cyanosis
How is paracetamol toxicity treated?
*Emesis within 2hrs of ingestion
*Activated charcoal
*Cathartics
*Aggressive IIVFT
What detoxifies toxic metabolites of paracetamol?
N-acetylcysteine
How does ethylene glycol cause toxicity?
1.Ethylene glycol metabolises to glycolic acid (metabolic acidosis) and oxalic acid
2.Oxalic acid combines with calcium in blood vessels + renal tubules
3.Hypocalcaemia, Obstructed tubules, Renal epithelial damage
METABOLITES CAUSE SEVERE CLINICAL SIGNS
What are the three phases of clinical signs of ethylene glycol poisoning?
*Phase 1 = 30min post ingestion - lasts 2-12hrs
-Ataxia, tachycardia, PUPD, vomiting
-NEED TO TREAT early or fatal
*Phase 2 = 8-24hr post ingestion
-Metabolic acidosis, anorexia, emesis, depression, miosis, hypothermia
*Phase 3 = 1-3 days post ingestion
-Oliguric renal failure, oral ulceration, salivation, vomiting, seizures
What is the treatment of ethylene glycol poisoning?
*Ethanol - prevents metabolism of EG to glycolic acid
-must be given as soon as possible after ingestion
*Fomepizole
*Supportive tx - IVFT
What are the signs of Anticoagulant rodenticide poisoning? (Warfarin)
*Vit K antagonist - CLotting factors = vit K dependent = inactivated = Coagulopathies
*Onest 1-3days post ingestion
How is anticoagulant rodenticide poisoning diagnosed?
*History
*Coagulation screen - WBCT, PT, aPTT
What is the treatment of anticoagulant rodenticide poisoning?
*Vitamin K1 - Orally
What does Cholecalciferol rodenticide poisoning cause?
- Increases calcium absorption by:
- Absorption from intestine
- Osteoclastic resorption from bone
- Reabsorption in distal renal tubules
How is cholecalciferol rodenticide poisoning treated?
*Manage as poisoning first = emetic, activated charcoal
*Then treat hypercalcaemia - give saline (Induces excretion of calcium)
-give calcitonin
What does metaldehyde / slug pellet poisoning cause?
*CNS stimulation - Loss of GABA inhibition
*Acute neurotoxicity, then hepatotoxicity
*Hyperaesthesia, anxiety, restlessness, salivation, muscle tremors, incoordination, opisthotonus, tachycardia, seizures, coma, death
*If survive neurotoxicity, hepatotoxicity may be fatal
What is the treatment of slug pellet poisoning?
*Emesis
*Gastric Lavage
*Followed by liquid paraffin
*Fluid therapy
*Diazepam / phenobarbital / propofol
What does NSAID poisoning cause?
- Inhibit prostaglandin synthesis through COX inhibition
- Variable toxicity (GI ulceration, nephrotoxicity)
How is NSAID toxicity diagnosed?
Diagnosis depends on history, clinical signs and blood sampling
How is NSAID toxicity treated?
*Emesis
*Gastric lavage
*Adsorbents
*Cathartics
*Treat Gi ulceration - Sucralfate
-H2 antagonist (Ranitidine)
-omeprazole (proton pump inhibitor)
*Treat AKI - IVFT
Why is chocolate toxic?
Theobromide = methylxanthines
Why is tea + coffee toxic?
Caffeine = Methylxanthine
What can methylxanthine poisoning cause?
- GIT upset
- Cardiac signs such as supraventricular or ventricular
arrhythmias - CNS sigs such as tremors and seizures
How is methylxanthine poisoning treated?
*Emesis
*Activated charcoal
What can consumption of grapes + raising cause?
*GI signs - vomiting / diarrhoea
*AKI - secondary to acute tubular necrosis
How is grape/raisin toxicity treated?
*Emesis
*Multiple doses of activated charcoal
*IVFT
What can marijuana/cannabis cause?
*Depression, disorientation, lethargy, incoordination
*Hypothermia (this needs monitoring)
*Compulsive eating (munchies)
What can Xylitol (Sweetner) cause?
Found in chewing gum
*Causes massive insulin release = hypoglycaemia
*Collapsed dogs can show hyperglycaemia
*Can develop fatal hepatic necrosis
How would you treat xylitol poisoning?
*Emesis
*Supportive tx - glucose
*N-acetylcysteine
What damage does onions, garlic + leeks cause?
*Disulfide, + thiosulfate = metaboised to damage RBCs
*Heinz bodies, haemolysis, methaemoglobinemia
