Parasitology Research

, Volume 87, Issue 1, pp 18–26

Therapeutic and prophylactic effects of isometamidium chloride (Samorin) against the hemoflagellate Cryptobia salmositica in chinook salmon (Oncorhynchus tshawytscha) and the effects of the drug on uninfected rainbow trout (O. mykiss)

  • B. F. Ardelli
  • P. T. K. Woo

DOI: 10.1007/s004360000294

Cite this article as:
Ardelli, B. & Woo, P. Parasitol Res (2001) 87: 18. doi:10.1007/s004360000294


A series of compounds (triphenylmethanes, thiazines, xanthenes, benzidines, phenanthridiniums, napthalamines, and diamidines) were screened for in vitro toxicity against Cryptobia salmositica. Isometamidium chloride (Samorin) was cryptobiacidal at low concentrations and was examined for therapeutic and prophylactic activities against C. salmositica in chinook salmon (Oncorhynchus tshawytscha). An intramuscular dose (1.0 mg/kg) of Samorin 3 weeks post-infection significantly reduced the parasitemia in adult chinook. A higher dose (2.5 mg/kg) eliminated the infection in 30% of adult fish and parasitemias were significantly reduced in the remaining infected fish. Juvenile chinook treated with 1.0 mg Samorin/kg at 2–3 weeks post-infection survived, while 100% of untreated control fish died from cryptobiosis. The high dose (2.5 mg/kg) was lethal to small fish (98.93 ± 12.09 g) and 50% died within 24 h of treatment, while all large fish (168.38 ± 13.87 g) survived. Samorin (1.0 mg/kg) did not affect growth, food consumption, complement, or hematocrit values in uninfected rainbow trout (O. mykiss).

Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • B. F. Ardelli
    • 2
  • P. T. K. Woo
    • 1
  1. 1.Department of Zoology and Axelrod Institute of Ichthyology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada e-mail: Tel.: +1-519-8244120; Fax: +1-519-7671656CA
  2. 2.Department of Zoology, College of Biological Science, University of Guelph, Guelph, Ontario, N1G 2W1, CanadaCA

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