Evidence of bromethalin toxicosis in feral San Francisco "Telegraph Hill" conures

PLoS One. 2019 Mar 18;14(3):e0213248. doi: 10.1371/journal.pone.0213248. eCollection 2019.

Abstract

During 2018, four free-ranging conures, from a naturalized flock in San Francisco, presented with a characteristic set of neurologic signs that had been reported in other individuals from this flock. The cause of morbidity or mortality in historic cases has not been identified. From these four subjects, fresh feces were collected during their initial days of hospitalization and submitted to the University of Georgia Infectious Diseases Laboratory and Center for Applied Isotope Studies for bromethalin and desmethyl-bromethalin quantitation. Using High Performance Liquid Chromatography, the laboratory detected bromethalin, a non-anticoagulant, single-dose rodenticide, in fecal samples from three subjects; half of these samples were also positive for desmethyl-bromethalin, bromethalin's active metabolite. In three subjects that died, the UGA laboratory screened brain and liver samples and found bromethalin in all samples; desmethyl-bromethalin was detected in all but one brain sample, which was below the detection limit. Our findings suggest the conures are more resistant to bromethalin than are other species in which bromethalin has been studied, and/or that the conures may be ingesting the toxin at a sublethal dose. More data is needed to better assess the long-term effects of bromethalin on animals exposed at the subacute/chronic levels, and also to better understand the compartmentalization of bromethalin and desmethyl-bromethalin in a wider variety of species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aniline Compounds / analysis*
  • Aniline Compounds / chemistry
  • Animals
  • Birds
  • Brain / metabolism
  • Brain / pathology
  • Chromatography, High Pressure Liquid
  • Feces / chemistry
  • Limit of Detection
  • Liver / chemistry
  • Liver / metabolism
  • Liver / pathology
  • Rodenticides / analysis*
  • Rodenticides / chemistry
  • San Francisco

Substances

  • Aniline Compounds
  • Rodenticides
  • bromethalin

Grants and funding

Mickaboo Companion Bird Rescue (www.mickaboo.org), a 501(c)3 non-profit organization, founded in 1996, based in Northern California, paid for all of the diagnostic evaluations for this study. No grant funding was used to support diagnostic work for this publication.