The interaction between temperature and dose on the efficacy and biochemical response of Atlantic salmon to hydrogen peroxide treatment for amoebic gill disease

• Published in: Journal of Fish Diseases
• Main Authors: Wynne, JW, Stratford, C, Slinger, J, Samsing, F, Rigby, M, McCulloch, R, Quezada-Rodriguez, P, Taylor, RS
• Format: Article in Journal/Newspaper
• Language: English
• Published: Blackwell Publishing Ltd 2020
• Subjects: Agricultural; Veterinary and Food Sciences; Fisheries sciences; Fish pests and diseases; Atlantic salmon
• Online Access: https://doi.org/10.1111/jfd.13110; http://www.ncbi.nlm.nih.gov/pubmed/31726482; http://ecite.utas.edu.au/143082

Hydrogen peroxide (H 2 O 2 ) is a commonly used treatment for a range of parasitic diseases of marine finfish, including amoebic gill disease (AGD). While this treatment is partially effective at reducing parasite load, H 2 O 2 can have detrimental effects on the host under certain conditions. Treatment temperature and dose concentration are two factors that are known to influence the toxicity of H 2 O 2 however, their impact on the outcome of AGD treatment remains unclear. Here, we investigated the effects of treatment temperature (8, 12 or 16C) and dose concentration (750, 1,000, 1,250mg/L) on the efficacy of H 2 O 2 to treat AGD. We demonstrated that a 20‐min bath treatment of H 2 O 2 at all doses reduced both parasite load and gross gill score significantly. Parasite load and gross gill score were lowest in the 1,000mg/L treatment performed at 12C. At the high dose and temperature combinations, H 2 O 2 caused moderate gill damage and a significant increase in the plasma concentration of electrolytes (sodium, chloride and potassium). Taken together, our study demonstrates that higher H 2 O 2 treatment temperatures can adversely affect the host and do not improve the effectiveness of the treatment.