Gaikowski, M.P., J.J. Rach, and C. Moen.  2001c.  Efficacy of hydrogen 
peroxide to control mortality associated with saprolegniasis in walleye 
eggs (Stizostedion vitreum).  Study report for a clinical field trial 
conducted at the South Dakota Game, Fish, and Parks, Blue Dog State 
Fish Hatchery.  Submitted to the U.S. Food and Drug Administration 
Center for Veterinary Medicine INAD 10-023.  August 28, 2001.  157 pp.


A clinical field trial was conducted at the Blue Dog Lake State Fish 
Hatchery (Waubay, South Dakota) to evaluate the efficacy of hydrogen 
peroxide to control mortality associated with saprolegniasis in walleye 
eggs.  The efficacy of hydrogen peroxide to control mortality associated 
with saprolegniasis was compared to an approved therapy, formalin 
administered daily at 1667 ppm.  Because all of the test units for a 
given treatment (i.e. hydrogen peroxide or formalin) emptied into a 
common catch tank, the terminal data collection for the trial was the 
number of eggs that reached the eyed-egg stage.  Therefore, an 
increase in the percent eye-up versus the control (1667 ppm formalin) 
would indicate that hydrogen peroxide was efficacious.  Eighteen test 
units, each holding ~169,180 eggs per unit, were used during the study.  
Three egg lots, representing three separate spawn dates, were used 
during the study.  From each lot, there were a total of six test units 
treated, three with hydrogen peroxide and three with formalin.  Nine 
test units were treated 15 times once per day on consecutive days with 
500 mg H2O2/L for 15 minutes using a flow-through system.  A second set 
of nine test units were treated 15 times once per day on consecutive 
days with 1667 ppm for 15 minutes using a flow-through system.  At the 
end of the 15-d trial, mean percent eye-up was 89.6, 86.6, and 76.0% when 
eggs from lots 3, 4, and 5 were treated at 500 mg H2O2/L and 91.7, 89.2, 
and 77.8% when treated at 1667 ppm formalin.  Because the eggs tested 
represented three separate lots, analysis of variance testing was completed 
for each lot.  Statistical analysis indicated that mean percent eye-up was 
significantly greater in eggs treated with formalin compared to eggs treated 
with hydrogen peroxide for all lots tested (Lot 3 - Chi-square=4.81, df=1, 
P=0.03; Lot 4 - Chi-square=8.66, df=1, P<0.01; Lot 5 - Chi-square=4.43, df=1, 
P=0.04).  Although the eye-up of eggs treated with formalin was judged to be 
statistically greater than the eye-up of hydrogen peroxide treated eggs, 
there was little if any biological significance between the egg eye-up observed 
between the two treatments.  In addition, the hydrogen peroxide treatment was 
administered at the low end of its proposed label concentration range whereas 
the formalin treatment administered was at the maximum label concentration.