Small animal Toxicology

Question 1

What are the routes of intoxication?

Answer 1

*Oral - most common
*Cutaneous / topical
*Inhalation
*Injection
*Ocular

Question 2

What are the steps to do when a patient comes in?

Answer 2

1. Stabilise the patient - resp, CV, CNS signs, thermoregulation
2. Obtain a complete history -toxin, time + amount ingested
3. Decrease absorbed dose - emesis, lavage

Question 3

What is the aim of decreasing absorbed dose?

Answer 3

*Prevent further absorption
*Increase elimination
*Bind toxin in inert form

Question 4

How is the toxin dose decreased?

Answer 4

*Emesis - apomorphine in dogs
-Xylazine / dexmedetomidine in cats
*Gastric lavage
*Adsorbents

Question 5

When should emesis be performed?

Answer 5

*Within 3hr of ingestion
-can be up to 6hr for aspirin +12hr for chocolate

Question 6

What are contraindications for emesis?

Answer 6

– animal has been vomiting
– absent gag reflex
– sedation or loss of consciousness
– seizuring
– Ingestion of corrosive substance or volatile petroleum based product

Question 7

What can be used to reverse apomorphine?

Answer 7

Naloxone - doesn’t stop the vomiting

Question 8

When would you use gastric lavage?

Answer 8

When cannot induce emesis
-must have ET tube in place
-repeat lavage 10-15 times until lavage clear

Question 9

What is an example of an adsorbent?

Answer 9

Activated charcoal

Question 10

What can be used to enhance toxin clearance?

Answer 10

*Cathartics - sorbitol
*Enema
*Diuresis

Question 11

What are examples of cathartics?

Answer 11

*Sorbitol
*Sodium / magneisum sulphate
*Liquid paraffin

Question 12

What can be used to prevent hypothermia?

Answer 12

*Blankets
*Heat pads

Question 13

What is used to prevent hyperthermia?

Answer 13

*Cold packs - luke warm to cool water - not cold/ice
*Careful not to over cool

Question 14

What drug is a respiratory stimulant?

Answer 14

Doxapram

Question 15

What can be used as Cardiovascular support?

Answer 15

*IVFT - crystalloids, colloids, blood
*Arterial blood pressure
*Electrolytes

Question 16

What analgesia should be given in toxin ingestion?

Answer 16

*Opioid - pethidine (short duration)
-buprenorphine (partial agonist)

Question 17

What should be done if animal is in depression / coma?

Answer 17

• Ventilatory support (manual/mechanical ventilation)
• Keep warm
• Maintain fluid and electrolyte balance

Question 18

What should be done if animal in hyperactivity / seizuring?

Answer 18

*Diazepam - antiepileptic
*Phenobarbital - antiepileptic
*Propofol

Question 19

When would you not use diazepam / phenobarbital?

Answer 19

When toxicity of the liver

Question 20

What can be used for samples in toxic animals?

Answer 20

*Heparinised blood
*Urine

Question 21

What lilies are toxic to cats?

Answer 21

*Easter lily
*Tiger lily
*Day lily

Question 22

What can pyrethrins cause in cats?

Answer 22

• Excessive salivation
  *tremors
  *ataxia
  *depression
  *hyperthermia/hypothermia

Question 23

What can be used to treat pyrethrin toxicity in cats?

Answer 23

*Bathing
*Emesis
*Activated charcoal
*Diazepam
*Methocarbamol

Question 24

What does paracetamol ingestion cause in cats?

Answer 24

*Oxidative injury to RBCs
*Hepatotoxic 24hrs post ingestion
*Vomiting, abdominal pain, tachycardia, pallor, cyanosis

Question 25

How is paracetamol toxicity treated?

Answer 25

*Emesis within 2hrs of ingestion *Activated charcoal *Cathartics *Aggressive IIVFT

Question 26

What detoxifies toxic metabolites of paracetamol?

Answer 26

N-acetylcysteine

Question 27

How does ethylene glycol cause toxicity?

Answer 27

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

Question 28

What are the three phases of clinical signs of ethylene glycol poisoning?

Answer 28

*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

Question 29

What is the treatment of ethylene glycol poisoning?

Answer 29

*Ethanol - prevents metabolism of EG to glycolic acid -must be given as soon as possible after ingestion *Fomepizole *Supportive tx - IVFT

Question 30

What are the signs of Anticoagulant rodenticide poisoning? (Warfarin)

Answer 30

*Vit K antagonist - CLotting factors = vit K dependent = inactivated = Coagulopathies *Onest 1-3days post ingestion

Question 31

How is anticoagulant rodenticide poisoning diagnosed?

Answer 31

*History *Coagulation screen - WBCT, PT, aPTT

Question 32

What is the treatment of anticoagulant rodenticide poisoning?

Answer 32

*Vitamin K1 - Orally

Question 33

What does Cholecalciferol rodenticide poisoning cause?

Answer 33

* Increases calcium absorption by: - Absorption from intestine - Osteoclastic resorption from bone - Reabsorption in distal renal tubules

Question 34

How is cholecalciferol rodenticide poisoning treated?

Answer 34

*Manage as poisoning first = emetic, activated charcoal *Then treat hypercalcaemia - give saline (Induces excretion of calcium) -give calcitonin

Question 35

What does metaldehyde / slug pellet poisoning cause?

Answer 35

*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

Question 36

What is the treatment of slug pellet poisoning?

Answer 36

*Emesis *Gastric Lavage *Followed by liquid paraffin *Fluid therapy *Diazepam / phenobarbital / propofol

Question 37

What does NSAID poisoning cause?

Answer 37

* Inhibit prostaglandin synthesis through COX inhibition * Variable toxicity (GI ulceration, nephrotoxicity)

Question 38

How is NSAID toxicity diagnosed?

Answer 38

Diagnosis depends on history, clinical signs and blood sampling

Question 39

How is NSAID toxicity treated?

Answer 39

*Emesis *Gastric lavage *Adsorbents *Cathartics *Treat Gi ulceration - Sucralfate -H2 antagonist (Ranitidine) -omeprazole (proton pump inhibitor) *Treat AKI - IVFT

Question 40

Why is chocolate toxic?

Answer 40

Theobromide = methylxanthines

Question 41

Why is tea + coffee toxic?

Answer 41

Caffeine = Methylxanthine

Question 42

What can methylxanthine poisoning cause?

Answer 42

* GIT upset * Cardiac signs such as supraventricular or ventricular arrhythmias * CNS sigs such as tremors and seizures

Question 43

How is methylxanthine poisoning treated?

Answer 43

*Emesis *Activated charcoal

Question 44

What can consumption of grapes + raising cause?

Answer 44

*GI signs - vomiting / diarrhoea *AKI - secondary to acute tubular necrosis

Question 45

How is grape/raisin toxicity treated?

Answer 45

*Emesis *Multiple doses of activated charcoal *IVFT

Question 46

What can marijuana/cannabis cause?

Answer 46

*Depression, disorientation, lethargy, incoordination *Hypothermia (this needs monitoring) *Compulsive eating (munchies)

Question 47

What can Xylitol (Sweetner) cause?

Answer 47

Found in chewing gum *Causes massive insulin release = hypoglycaemia *Collapsed dogs can show hyperglycaemia *Can develop fatal hepatic necrosis

Question 48

How would you treat xylitol poisoning?

Answer 48

*Emesis *Supportive tx - glucose *N-acetylcysteine

Question 49

What damage does onions, garlic + leeks cause?

Answer 49

*Disulfide, + thiosulfate = metaboised to damage RBCs *Heinz bodies, haemolysis, methaemoglobinemia