BASICS
- ACRs are a commonly used class of rodenticides
- ACRs interfere with normal blood clotting and cause coagulopathy by inhibiting vitamin K epoxide reductase in liver and preventing formation of active clotting factors
- First-generation anticoagulants such as warfarin, coumafuryl, coumachlor, and coumatetralyl are short-acting, requiring multiple feedings to result in toxicosis
- Long-acting or second-generation ACRs include chlorophacinone, diphacinone, pindone, brodifacoum, bromadiolone, difethialone, difenacoum, and others. These are more toxic
- Most ACRs used today are second generation, with activity in the body lasting ~1 month or longer
- Minimum toxic dosage has not been established in horses. Coagulopathy has been reported in horses associated with a brodifacoum dosage of 0.125 mg/kg, and a diphacinone dosage of 0.2 mg/kg
Poisoning can occur after accidental ingestion of bait or as a result of malicious intent.
- Hemorrhage of variable severity. Can be internal, external, or both, and can be focal or widespread
- Signs generally manifest within 2–5 days after ingestion and include pale mucous membranes, weakness, anorexia, dyspnea, tachycardia, hematomas and swellings, hematuria, bleeding from the mouth, and epistaxis
- Signs are delayed and do not occur until days after exposure, after existing clotting factors are depleted
DIAGNOSIS
TREATMENT
MEDICATIONS
FOLLOW-UP
MISCELLANEOUS