Fish Diseases PDF

COMMON DISEASES OF FRESHWATER ORNAMENTAL FISHES AND ITS MANAGEMENT (Ref.ICAR) Health management of aquarium fish is gaining more importance in ornamental fish sector due to the financial investments involved in it. Awareness and knowledge on fish health managem...

COMMON DISEASES OF FRESHWATER ORNAMENTAL FISHES AND ITS MANAGEMENT (Ref.ICAR) Health management of aquarium fish is gaining more importance in ornamental fish sector due to the financial investments involved in it. Awareness and knowledge on fish health management is the need of the hour to sustain the industry without major economic loss. Diseases are associated with the complex interactions of host, pathogen and environment. Further, the diseases are categorized into two major types such as infectious and non-infectious diseases. Infectious diseases spread from one animal to another and caused by any of the pathogenic organisms such as virus, bacteria, fungi and parasites. Non- infectious diseases are confined to a particular individual animal and may be caused due to environmental stress and nutritional factors. (I). INFECTIOUS DISEASES 1) Viral diseases S. Name of the Cause Clinical signs Treatment No. disease 1. Koi Herpes Virus Koi Herpes Gill infection with No effective Disease (KHVD) Virus red and white treatment is available patches. for viral diseases Sunken eyes. except few vaccines. Pale patches or blisters on the skin. Follow the better management 2. Lymphocystis Iridovirus Cauliflower like practices. disease nodular white swellings on body Separate the surface and fins. affected fish. 3. Spring Viraemia Rhabdovirus Haemorrhages in of Carp Virus the skin and gills. Avoid unnecessary (SVCV) Dark skin. stress. Swollen belly. Exophthalmia. Maintain good water Protrusion and quality. inflammation of the vent. Provide good quality feed. 4. Herpesvirus Herpesvirus Ulcerated lesions. disease or Carp Presence of pox plaques on the skin surface. 2) Bacterial diseases S. Name of the Cause Clinical signs Treatment No. disease 1. Ulcer or Aeromonas sp. Skin lesion with blood. Disinfection of Aeromoniasis Shallow open sores. pond with KMnO4 Eroded fins and mouth. @ 5mg/l. 2. Fin and tail rot Aeromonas sp. Whitish margin of fins. Fish feed mixed and Putrefaction of fins. with antibiotics Pseudomonas Reddened areas at base terramycin @ 100 sp. of fins. mg/ kg or sulphadiazine @ 100 mg/ kg. 3. Columnaris Flavobacterium Grayish patches over Dip treatment in disease columnare head and dorsal 500 ppm KMnO4 surface. for 2 min. Grayish discolouration in outer margin of fins. 4. Mycobacteriosis Myobacterium Anorexia Bath treatment fortuitum Emaciation with antibiotics Loss of equilibrium such as Exophthalmia Oxytetracycline Dropsy @ 50 mg/ l for 15 Grey-white nodules on minutes. internal organs Nifurpirinol @66 mg/ l for 15 minutes. 5. Dropsy Aeromonas Distended abdomen. Dip in 5 mg/l hydrophila Scale protrusion. KMnO4 for 2 min. Mild ulceration. Disinfection of pond with KMnO4 @ 1mg/l. 6. Bacterial gill Myxobacteria Necrotic gill tissues. Bath treatment of disease sp. Fusion of gill fishes with alkyl filaments. benzalkonium chloride @ 2 mg/l for 1 hour. 3) Fungal diseases S. Name of the Cause Clinical signs Treatment No. disease 1. Cotton wool Saprolegnia Cotton wool like Bath treatment in disease or parasitica outgrowth over injury NaCl @ 3-4%. Saprolegniasis site and haemorrhage. KMnO4 bath treatment @ 160 mg/l for 5 days. Long term bath in 3 ppm methylene blue. 2. Gill rot Branchiomyces Gill necrosis. Bath treatment demigrans and Discolouration & in NaCl @ 3-4% Branchiomyces disintegration of gill for 5-10 min. sanguinis tissues. KMnO4 bath treatment @ 5 mg/l for 5-10 min. 4) Parasitic diseases S. Name of the Cause Clinical signs Treatment No. disease Protozoan parasites 1. White spot Ichthyophthirius Erratic swimming. Bath treatment in disease or multifilis Parasites visible as malachite green Ichthyophthirias white spots on skin, oxalate at 0.15- is gills and fins. 0.20 mg/l for 4-6 hours. Bath treatment can also be given in sodium chloride solution for 7 days or more. 2. Trichodiniasis Trichodina sp. Darkening of skin. Bath treatment in Excessive mucus formalin at 15-25 production. mg/l Pale gills. concentration. Bath treatment in KMnO4 solution for 7 days or more.  3. Oodinasis Oodinium Clamped fins. Bath treatment in (Velvet sp. Skin shows gray malachite green or disease) patches which look formalin. like dust giving velvet appearance to skin. The fish may show signs of irritation. Monogenetic trematodes 1. Gill fluke and Dactylogyrus sp. Fishes grasp air. Permanent bath skin fluke (infecting gills) Faded gills. treatment in infestation and Gills covered with dipterex @ 0.25- Gyrodactylus sp. thick mucus layer. 0.50 mg/l. (infecting skin) Body covered with Formalin bath bluish grey mucus treatment @ 100 layer. mg/l. Crustacean parasites 1. Lernaeasis or Lernaea sp. Emaciation. Permanent bath Anchor worm Inflammation and treatment in infestation necrosis at the site of Dipterex at 0.25- attachment. 0.50 mg/l. Small hemorrhagic Bath treatment in spots. NaCl @ 0.8- 1.1% fo 3 min. 2. Argulosis or Agulus sp. Haemmorhagic Prolonged Fish lice ulcerative lesions bath infestation around bite wounds. treatment in Visible as a small Trichlorphon button like structure on @ body surface. 0.2 mg/l for 24 hr. Prolonged dip treatment in 5% salt. Bath treatment in 10-20 mg/L of KMNO4 for 30 minutes alternatively for 3 days. (II). NON-INFECTIOUS DISEASES S. Name of the Cause Clinical signs Treatment No. disease Nutritional deficiency diseases 1. Scoliosis and Deficiency of Scoliosis is the lateral By supplementing Lordosis the essential curvature of the spinal required quantities (Skeletal amino acid cord and lordosis is of tryptophan and deformation) namely the vertical curvature vitamin C in fish tryptophan and of the spinal cord. diet. vitamin C deficiency. 2. Pin head disease Deficiencies in Poor & stunted growth. Administer protein, Sluggish movements. nutritionally carbohydrate balanced feeds and lipids. and proper feeding management. 3. Constipation Imbalanced or Appearance of a long Feeding with poor quality thread like structure Daphnia helps as diet. attached to vent. they act as mild Fish becomes sluggish. laxative. Swelling of belly. Salt treatment. Environmental factors 1. Brown blood Presence of Darker gills. Flushing of gills disease excessive nitrite Excessive pumping of under increased in water (>0.1 gills. flow of water. mg/L). Piping at the surface of water. 2. Gas bubble Super saturation Gas emboli in fins, Agitate water. disease with either opercula, eye or gills. Increase water oxygen or temperature. nitrogen in water. The most important approach to control the disease is to manage the culture unit by following better management practices to reduce predisposing conditions of the disease. This can be achieved by optimum stocking density, preventing the introduction of pathogens, maintenance of good water quality, avoiding stress and through the provision of adequate nutrition.