Tier 1 — must know
Canine
Multisystem / Toxic / Emergency
Toxicology
Rodenticide toxicity
Toxicology pattern split · anticoagulant versus bromethalin versus cholecalciferol · identify the product first
⏱ 2–3 min read · Topic 25 of 33
5
Practice Qs
4
Traps
High
Exam freq.
—
Your status
Study step
Exam core — read this first
Big toxicology split → anticoagulant, bromethalin, and cholecalciferol rodenticides create different syndromes
Anticoagulant pattern → delayed bleeding and prolonged clotting times
Bromethalin pattern → acute neurologic signs from cerebral edema with no vitamin K benefit
Cholecalciferol pattern → hypercalcemia, hyperphosphatemia, and renal injury
Clinical mechanism — only what matters
Anticoagulant rodenticide → blocks vitamin K recycling and impairs clotting factor activation
Bromethalin → causes CNS edema and neurologic dysfunction
Cholecalciferol → drives calcium/phosphorus derangement with soft-tissue and renal injury
The board often tests whether you pick the right toxicology branch and avoid the wrong antidote.
Pattern recognition
Core pattern
Exposure history or bait accessBleeding, neuro signs, or hypercalcemia/AKI patternTiming depends on product class
Supporting clues
Epistaxis or dyspnea from bleedingTremors/seizures with bromethalinDepression and PU/PD with cholecalciferolRecent ingestion may still be asymptomaticProduct packaging can be decisive
NAVLE trigger: This is a “know the bait class” topic more than a single-syndrome topic.
Decision core — what NAVLE actually asks
Known recent ingestion, product identified
→ Decontamination and class-specific treatment should start before waiting for delayed disease to declare itself
Bleeding rodenticide pattern
→ Think anticoagulant toxicosis, vitamin K1, and blood-product support if severe
Neurologic or hypercalcemic pattern
→ Think bromethalin or cholecalciferol instead; vitamin K1 is not the universal answer
Key interpretation
Product identity
Critical
Often answers the question fastest
PT / coagulation
Prolonged first
Classic anticoagulant clue
Neurologic signs
Bromethalin concern
No vitamin K rescue here
Calcium / phosphorus
High in cholecalciferol
AKI risk follows
Bleeding delay
Common with anticoagulants
May not be immediate after ingestion
Blood products
May be needed
Severe anticoagulant bleeders may require plasma/transfusion support
⚠ Vitamin K1 is not the answer for every rodenticide. The bait class changes the entire treatment plan.
Treatment
Step 1
Identify the product and decontaminate recent ingestions when appropriate
This is the fastest route to the right branch of treatment.
Step 2
Anticoagulant cases: vitamin K1 plus blood products if active bleeding is severe
That is the high-yield classic antidote branch.
Step 3
Bromethalin/cholecalciferol cases: supportive care and toxin-specific monitoring, not reflex vitamin K1
Neurologic or hypercalcemic patterns need different management.
NAVLE traps — where students lose marks
Do not assume all rodenticides are anticoagulants
That is the main exam trap.
Vitamin K1 helps anticoagulant toxicosis, not bromethalin
Wrong antidote logic costs marks.
Anticoagulant cases can bleed after a delay
A recent ingestion may still look clinically quiet at first.
Hypercalcemia after rodenticide exposure points away from anticoagulants
That is cholecalciferol reasoning.
Differentials — how to separate these on NAVLE
Fast separator: The board is usually asking you to identify which rodenticide class fits the syndrome and then choose class-correct treatment.
| Rodenticide type | Dominant syndrome | Lab clue | Key separator |
|---|---|---|---|
| Anticoagulant | Bleeding | Prolonged PT | Vitamin K1 branch |
| Bromethalin | Neurologic signs | No coagulopathy pattern | No vitamin K antidote |
| Cholecalciferol | Renal injury / depression | Hypercalcemia / hyperphosphatemia | Mineral derangement branch |
| Ethylene glycol | AKI / acidosis | Oxalate / acidosis clues | Not a rodenticide but a toxic renal mimic |
| Primary coagulopathy | Bleeding | No bait history necessarily | Broader differential if product unknown |
Clinical application tools
These are general support tools only; toxin identification and class-specific treatment still drive the case.
30-second revision
Question 1Which rodenticide class is this?
Anticoagulant clueDelayed bleeding / prolonged PT
Bromethalin clueNeurologic signs
Cholecalciferol clueHypercalcemia / AKI
Critical trapVitamin K1 is not universal
Practice questions
Pre-built NAVLE-style · Rodenticide toxicity
0 / 0
A dog develops spontaneous bleeding several days after known rodenticide exposure. Which class is most likely?
For which rodenticide class is vitamin K1 the appropriate antidote branch?
A bait-exposed dog has neurologic signs without a coagulopathy pattern. Which rodenticide rises highest?
Which lab abnormality most strongly supports cholecalciferol rodenticide toxicity?
Which statement about rodenticide toxicity is most accurate?