There are no cures for fish viral diseases in ornamental fish, though research into a KHV vaccine is ongoing.
During the previous decades, fish parasites identification have become increasingly visible , because of the growth of freshwater ornamental fish industries throughout the world. Parasitic diseases affect physiologic and biologic characteristics, caused mechanical damage and economic losses in ornamental fish industries.
This book covers all aspects of ornamental fish healthincluding: environmental needs, the aquatic trade, fishkeeping,disease investigation, systematic disorders, infectious andnon-infectious diseases, medical and surgical therapies, relevantlegislation and health & safety.
An overview of ornamental fish diseases and therapy. - NCBI
Ornamental Fish: Diseases and Problems
Several viral diseases have been thoroughly described in ornamental tropical fishes. The most commonly observed viral disease of tropical fish is called lymphocystis disease. This disease is caused by an iridovirus which infects connective tissue cells of the fish. The virus induces these cells to undergo extensive hypertrophy until the cells may actually be visible to the naked eye. Affected cells can increase a thousand fold in size. The disease appears to be more common in marine and brackish water fishes. Certain species of freshwater tropical fish like the green terror () are prone to the disease. Members of the genera , , and are all brackish water fishes that seem predisposed to lymphocystis disease. Stress is almost certainly a factor in this disease since outbreaks are frequently observed following capture and shipping of fishes. Gross lesions appear white and granular and usually are seen on the skin and fins. Occasionally, lesions will be seen in the mouth and on the gills. There is no proven chemotherapeutic treatment. Most cases are self limiting if the fish is provided with proper water quality and nutrition. Surgery can be performed on affected fish by carefully scraping the hyperplastic fibroblasts clear of the fish with a sterile scalpel or scissors. This procedure should be performed quickly and the patient(s) should receive 5-10 days of topical antibiotic therapy following the surgery. A definitive diagnosis can be made by microscopically examining a scraping of the affected area. The enlarged connective tissue cells will appear circular and in clusters. These cells frequently emit a light orange hue under the microscope.Strains closely resembling ISKNV have been reported to cause disease in numerous species of ornamental freshwater and marine fishes. In the early 1990s, RSIV was first observed in Japan and since then has been reported primarily in Asian marine finfish. Today, RSIV is reportable to the World Organization for Animal Health (OIE) and the United States Department of Agriculture-Animal and Plant Health Inspection Service (USDA-APHIS). The third subgroup TRBIV has been reported predominantly in Asian flounder species. New viral isolates from other fish species are currently being evaluated by scientists to determine their relationships to these three main groups. This publication provides disease, diagnostic, and management information on megalocytiviruses in fish for producers, wholesalers, retailers, and others who work with fish and may be unaware of this disease.Bacterial disease is the most common infectious problem of ornamental fishes. Collectively, only water quality problems exceed bacterial diseases in the area of pet fish morbidity and mortality. The majority of bacterial infections are caused by Gram-negative organisms including the following pathogenic genera: a Gram-positive genus, has been shown to cause disease in ornamental fishes. Bacterial organisms may be the primary cause of disease, or they may be secondary invaders, taking advantage of a breach in the fish's integument or compromise of its immune system. The majority of bacterial fish pathogens are natural inhabitants of the aquatic environment, whether it be freshwater or marine. Nearly every bacterial pathogen of fish is capable of living independently away from the fish host (Inglis et al., 1993). Virtually any extrinsic stress, including shipping, crowding, poor water quality, and inadequate nutrition, may predispose an ornamental fish to bacterial disease.Although this worldwide interest in ornamental fish has led to development in their cultivation techniques, there are still many difficult-to-culture species with high demand. Ornamental fish pathogens spread very rapidly in the world because of their commercial benefits. Consequently, routine infectious disease controls are very important for risk analysis and precaution steps. Parasites are harmful and limiting factors in breeding and rearing ornamental fish industry. From economic aspects, parasitic diseases in fish have a particular importance, because of causing sterility, discoloration, change of body shape and decreased growth and weight of fish. Therefore, knowledge about fish parasites is crucial for successful aquaculture. For this reason, we aimed to isolate and identify the parasitic fauna of five species of ornamental freshwater fish in northern Iran.