The bag of fish should then be put on ice for immediate transport to the lab. This method will keep the fish sample in relatively good condition for up to six hours. Frozen samples may be submitted for diagnosis when the fish are over 24 hours from the lab. However, this method produces samples of only limited value in the diagnostic procedure. Each time diseased fish are submitted for diagnosis, they should be accompanied by a pond water sample.
Water quality plays an important role in disease epidemics in catfish culture.
The water sample allows the diagnostician to determine if water quality is contributing to the disease state or causing the problem outright. Dissolved oxygen and carbon dioxide levels should be taken at the pond site because they will not give a true reading at the lab. Water samples should be obtained in a clean glass or plastic container. Rinse the container in the pond water several times before obtaining the sample. Take the sample a few feet from the pond's edge and away from water inlets.