title: Haematological effects of 2-phenoxyethanol and etomidate in carp (Cyprinus carpio L.).
abstract: OBJECTIVE
  To evaluate the effects of handling alone versus handling under anaesthesia with 2-phenoxyethanol or etomidate on haematological parameters in carp.
  
  
  METHODS
  Prospective, randomized, laboratory experiment.
  
  
  METHODS
  Seventy-two juvenile carp (Cyprinus carpio) weighing 35.9 ± 10.4 g were divided into six groups of 12 fish.
  
  
  METHODS
  Either 2-phenoxyethanol or 2% etomidate were administered to induce deep anaesthesia (0.3 mL L(-1) and 0.6 mL L(-1) , respectively) or deep sedation (0.15 mL L(-1) and 0.3 mL L(-1) , respectively). Fish were handled with and without sedation. Blood was sampled at 1 hour and 1 week post-treatment. Phagocyte oxidative activity [nitrotetrazolium blue reduction test (NBT)] and differential erythrocyte [red blood cell (RBC)] and leukocyte (white blood cell) counts were evaluated.
  
  
  RESULTS
  At 1 hour after the induction of anaesthesia, haematocrit (Ht) and haemoglobin (Hb) were increased in fish anaesthetized with 2-phenoxyethanol, and mean corpuscular haemoglobin (MCH) was increased in fish anaesthetized with etomidate. At 1 week, an increase in RBC, erythroblastosis, erythrocyte damage, lymphopenia, neutrophilia, monocytosis and thrombocytosis occurred in both groups. Red blood parameters did not change 1 hour after handling alone, but after 1 week Ht, Hb and mean cell volume decreased, whereas MCH concentration (MCHC) and abnormal erythrocytes increased. Lymphopenia, neutrophilia, monocytosis, thrombocytosis and a decrease in NBT occurred. Fish handled under sedation showed an increase in Hb and MCHC followed by a decrease at 1 week in Ht, Hb and MCH, erythroblastosis and increased abnormal erythrocytes. Lymphopenia and neutrophilia were less pronounced than in fish handled without sedation, but a decrease in NBT was noted at 1 week post-treatment.
  
  
  CONCLUSIONS
  Deep anaesthesia with 2-phenoxyethanol or etomidate induced significant haematological alterations in juvenile carp. Deep sedation reduced the immediate immunosuppressive effects of handling but did not eliminate longterm effects. These anaesthetics should be avoided during experimental procedures involving haematological measurements. In contexts that require the short-term handling of carp, these drugs should be used with caution in view of their possible side effects.
authors.affiliation: Institute of Biology, Department of Animal Physiology, Siedlce University of Natural Sciences and Humanities, Siedlce, Poland.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Witeska
authors.affiliation: Institute of Biology, Department of Animal Physiology, Siedlce University of Natural Sciences and Humanities, Siedlce, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Dudyk
authors.affiliation: Institute of Biology, Department of Animal Physiology, Siedlce University of Natural Sciences and Humanities, Siedlce, Poland.
authors.forename: Natalia
authors.initials: N
authors.lastname: Jarkiewicz
mesh_terms: D000758:Anesthesia / Q000662:veterinary; D000777:Anesthetics / Q000097:blood / Q000494:pharmacology*; D000822:Animal Husbandry; D000818:Animals; D017756:Aquaculture; D002347:Carps / Q000097:blood / Q000502:physiology*; D004906:Erythrocyte Count / Q000662:veterinary; D005026:Ethylene Glycols / Q000097:blood / Q000494:pharmacology*; D005045:Etomidate / Q000097:blood / Q000494:pharmacology*; D006234:Handling, Psychological; D006400:Hematocrit / Q000662:veterinary; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D000777:Anesthetics; D005026:Ethylene Glycols; C005398:phenoxyethanol; D005045:Etomidate
keywords: anaesthesia; blood; erythrocytes; fish; leukocytes