title: Evaluation of isoeugenol for anesthesia in koi carp (Cyprinus carpio).
abstract: OBJECTIVE
  To evaluate isoeugenol as an anesthetic agent in koi carp.
  
  
  METHODS
  216 juvenile koi carp (Cyprinus carpio).
  
  
  METHODS
  Fish were randomly allocated to 9 groups of 24, and each group was randomly exposed to isoeugenol concentrations ranging from 0 to 500 mg/L. General activity, excitement, fin and gill color changes, opercular movement rate, loss of equilibrium, muscle tone, jaw tone, and handleability were assessed. Five fish from the control (0 mg/L), 200 mg/L, and 500 mg/L groups were randomly selected prior to anesthetic recovery and again 24 hours after recovery for euthanasia, gross necropsy, and histologic assessment of gills, internal viscera, and skeletal muscles.
  
  
  RESULTS
  Mean +/- SD interval to achieve stage 2 anesthesia with isoeugenol ranged from 22.4 +/- 6.2 minutes at 20 mg/L to 0.25 +/- 0.4 minutes at 500 mg/L, whereas the mean interval to stage 3 anesthesia ranged from 28.1 +/- 3.9 minutes at 20 mg/L to 0.33 +/- 0.48 minutes at 500 mg/L. With the exception of the 500 mg/L group, opercular movements were maintained throughout. Death was observed only in the 500 mg/L group, in which 50% of the fish either failed to recover or died within 24 hours after anesthetic exposure. There were no pathological differences between fish exposed to isoeugenol at 0 or 500 mg/L.
  
  
  CONCLUSIONS
  Isoeugenol appeared to have a wide margin of safety with predictable dose-related effects. Concentrations of 40 to 80 mg/L induced anesthesia within 4 to 11 minutes and were considerably less than the concentration associated with fish death.
authors.affiliation: Department of Small Animal Medicine and Surgery, University of Georgia, Athens, GA 30602, USA. vet_jgm@hotmail.com
authors.forename: Juliet N
authors.initials: JN
authors.lastname: Gladden
authors.forename: Ben M
authors.initials: BM
authors.lastname: Brainard
authors.forename: James L
authors.initials: JL
authors.lastname: Shelton
authors.forename: Alvin C
authors.initials: AC
authors.lastname: Camus
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Divers
mesh_terms: D000758:Anesthesia / Q000379:methods*; D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002347:Carps; D005054:Eugenol / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000633:toxicity; D006801:Humans; D008004:Licensure; D012119:Respiration / Q000187:drug effects; D012449:Safety; D014481:United States
chemical_list: D000777:Anesthetics; D000890:Anti-Infective Agents; D005054:Eugenol; C036643:isoeugenol