Bromethalin poisoning in 192 dogs - symptoms and outcomes

Abstract

OBJECTIVE: To evaluate the frequency of clinical signs, dose ingested, and outcome in a large group of dogs with bromethalin ingestion. DESIGN: Retrospective cohort study of dogs from 2010 to 2016. SETTING: Three university teaching hospitals and 1 private practice. ANIMALS: A total of 192 dogs with bromethalin ingestion. MEASUREMENTS AND MAIN RESULTS: Total 192 cases were identified, of which 25 dogs developed clinical signs. Five cases initially had severe neurological signs and were euthanized. A sum of 187 dogs survived to discharge. The total ingested dose was recorded in 59 dogs with a median (interquartile range) 0.2 mg/kg (0.28 mg/kg). The remaining 133 dogs had confirmed ingestion reported by owners (witnessed ingestion or colored feces) but the total dose could not be calculated. The median (interquartile range) time to presentation for all dogs was 2 hours (4.8 h). A majority of patients were treated on an outpatient basis (121/192) and 71 of 192 were treated as inpatients with 58 of 71 receiving fluid diuresis. Decontamination was performed in 179 dogs including emesis induction (14), activated charcoal administration (42), and both (123). Emesis was successful in 128 dogs and apomorphine was the most common emetic agent (121). Mild to severe clinical signs at admission were reported in 19 cases including vomiting (6), tremors (5), lethargy (4), ataxia (3), weakness (2), diarrhea (2), collapse (2), and and anorexia (2). One case developed ataxia and tremors within 72 hours of admission. CONCLUSIONS AND CLINICAL RELEVANCE: Symptoms of bromethalin toxicosis are uncommon, and most ingested doses are well below the reported dose expected to cause clinical signs. In this patient population, prognosis was excellent unless severe clinical signs were noted, which carried a high euthanasia rate. Effects of treatment on outcome could not be evaluated due to the low number of patients that developed clinical signs.