Introduction
- Anticoagulant rodenticides available commercially in cereal-based baits at a concentration of 0.005%.
- Some professional-use products may be at concentrations as high as 0.1%.
- Second generation anticoagulants are more toxic in repeated small doses than a single dose.
- Cause : ingestion of contaminated bait → blocks action of Vitamin K1.
- Signs : delayed from 2-10 days post-exposure: internal and external hemorrhage and bruising.
- Treatment : SQ vitamin K1, whole blood transfusion.
Do not use vitamin K3 as it is less effective. - Prognosis : good with appropriate therapy.
Diagnosis
Clinical signs
Generalized hemorrhagic syndrome- Signs related to site of bleeding:
- Pallor due to anemia or hypovolemia (especially apparent in final stages).
- Hypothermia.
Diagnosis
Differential diagnosis
- Chronic cholestasis.
Sequelae
Prognosis
- Good: if treatment started soon after exposure and clotting time carefully monitored.
- Guarded: if severe case.
- Depends on site and severity of hemorrhage.
Expected response to treatment
- Decreased clotting time.
- Color returns to mucous membranes.
- Patient becomes more alert/responsive.
- Resorption hematoma/hemorrhages.
- Increase in erythrocyte count and PCV in longer term.
Reasons for treatment failure
- Non-detection of hemorrhage, eg internal.
- Delay in treatment.
- Inadequate doses vitamin K1 given.
- Inadequate supportive therapy (plasma or blood) in 24 h delay in vitamin K1 therapy becoming effective.
- Insufficient duration of treatment.
Sources
Publications
Refereed papers
- Recent references from PubMed.
- Blocker T L et al (1999) Acute tracheal obstruction associated with anticoagulant rodenticide intoxication in a dog. JSAP 40 (12), 577-80 PubMed.
- Sheafer S E , Couto C G (1999) Anticoagulant rodenticide toxicity in 21 dogs. JAVMA 35 , 38-46 PubMed.
- Lewis D C et al( 1997) Thrombocytopenia in dogs with anticoagulent rodenticide induced haemorrhage- eight cases (1990-1995). JAAHA 33 , 417-422 PubMed.
- Berry C R et al (1993) Thoracic radiographic features of anticoagulant rodenticide toxicity in 14 dogs. Vet Rad 34 , 391-396
- Mayer S (1991) Poisons - coumarin derivatives. In Practice 12 , 174-174.
Other sources of information
- Campbell A (VPIS) (2002) The management of anticoagulant rodenticide poisoning in companion animals. UK VET 7 (3), 23-25.
Organization(s)
UK
- Rentokil Initial plc , Research and Development Division, Felcourt, East Grinstead, West Sussex, RH19 2JY, UK. Tel: +44 (0)1342 833022; Fax: +44 (0)1342 326229.





