VETERINARY SOULTIONS TO TROUT DISEASE CASES

This presentation will report on trout disease cases on fish farms, primarily in Wisconsin, that have been assisted by the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP).  In Wisconsin the DATCP is responsible for health requirements of imported fish, farm-raised fish, and all fish stocked into waters of the state.  Wisconsin has an abundance of trained private practice veterinarians who are available to fish farmers for VHS sampling and other disease work including observational surveillance. The DATCP works with private practice veterinarians to investigate fish diseases on fish farms.  All fish being stocked into waters are required to have a fish health certificate prior to stocking.  As a result of the elevated level of veterinary involvement with fish health in Wisconsin fish farmers can more readily pursue diagnostic and treatment assistance from veterinarians when disease occurs on their fish farm.  

In one case we will look at a rainbow trout farm in Southern Wisconsin that has reported seeing red skin lesions on their fish.  The trout are raised in earthen raceways that receive continuous flow 50F groundwater.  The trout are feed a commercially pelleted feed until they weigh 1.25 pounds and are processed for sale to restaurants and grocery stores.  The farm had recently imported fish from a neighboring state.  The lesions appeared on less than 5% of the fish, particularly the larger fish that are near market size.  A list if differential diagnoses include Furunculosis, Strawberry Disease, traumatic injury and even Viral Hemorrhagic Septicemia.