title: Organophosphate poisoning of Atlantic salmon in connection with treatment against salmon lice.
abstract: Three incidents with high mortality in Atlantic salmon after trichlorfon treatment against salmon lice are described. All 3 incidents occurred at water temperatures of 12 degrees C or higher. The mean brain acetylcholinesterase (AChE) activity of dead fish was less than 20% of normal activity, while survivors showed mean activities of 22-61% of normal levels. Dichlorvos residues in muscular and liver tissues ranged from nondetectable levels to 0.2 micrograms/g tissue. The strongest inhibition of brain AChE was found in association with the highest dichlorvos residues. Substantial AChE-inhibition was, however, also found in samples in which dichlorvos residues could not be detected. AChE-determination was found to be more reliable than residue analysis for the diagnosis of organophosphate poisoning in salmon.
authors.forename: T E
authors.initials: TE
authors.lastname: Horsberg
authors.forename: T
authors.initials: T
authors.lastname: Høy
authors.forename: I
authors.initials: I
authors.lastname: Nafstad
mesh_terms: D000818:Animals; D003445:Crustacea; D004478:Ectoparasitic Infestations / Q000188:drug therapy / Q000662:veterinary*; D005393:Fish Diseases / Q000139:chemically induced* / Q000188:drug therapy; D012474:Salmon; D014236:Trichlorfon / Q000506:poisoning* / Q000627:therapeutic use
chemical_list: D014236:Trichlorfon