Post on 12-Jan-2017
Non-Infectious Diseases Of Fish
Non-Infectious Disease
Not caused by pathogens Cannot be transmitted to other species Malnutrition, Avitaminoses, Heavy Metals etc. are
responsible Risk factors:
GeneticsLife-styleEnvironmental factors
Disease = Opportunity & Condition
Non-Infectious Diseases:
Disease
• Gas-Bubble Disease• Low-Temperature• Acidosis and Alkalosis• Chlorine Toxicity
Disease
• Water-Borne Irritants• Blue-sac, White sac and Yolk sac• Hypothermia• Heavy metals
Deformity Disease Of
Larvae
• Coloration Anomalies• Physical Deformities• Early Life Stage Mortality Syndrome• Traumatic Injuries• Jellyfish Sting• Sunburn• Lightning Strike• Ulcerative Dermal Necrosis
Genetic Risk Factors
Determined by genes Familial Disease Tendency
Disease runs in species Recessive gene disorders Down syndrome
Born with extra chromosome Sex-linked disorders
Linked to x chromosome (female) Can be recessive in females Color blindness, hemophilia, & muscular dystrophy
Environmental Risk Factors
Pollution Radiation Altitude Temperature Chemical factors
Cyanide Nitrite Cadmium Ammonia
Lifestyle Risk Factors Insufficient food availability Stress condition
Non-Infectious Diseases:Ammonia Toxicity: Most commonly observed in new systems More problematic in cold weather Bacteria decreased function Check regularly in the winter Toxic levels vary with pH Un-ionized form highly fatal at 0.2 ppm 1 ppb-0.02 ppm
Clinical signs: Dyspnea Telangiectasia Gill damage Mucous production Gills and body Lethargy
Treatment: Chronic toxicity Water changes Correct inciting cause Evaluate filtration Often insufficient capacity System burden Fish density Organic load Detritus Diet
Non-Infectious Diseases:Nitrite toxicity: Clinical signs
Similar to ammonia Methemoglobinemia
Brown blood Muddy gillsDiagnosis: Test water Blood sample Histopathology
Treatment:
Acute toxicity Remove fish to ammonia and
nitrite-free water Oxygenate water Increase salt Chloride competes with nitrite
at gill 3 ppt
Chronic toxicity Evaluate biological filter,
stocking density, feeding practices
Non-Infectious Diseases:Hypoxia:Low oxygen levels How can oxygen levels become depleted in a system? Rare in aquariums because of aeration More common in ponds Oxygen depletion occurs during the hours when the sun is down Phytoplankton biomass can consume huge amounts of oxygen High mortalities noted at dawn or early morning Largest fish typically go first
Non-Infectious Diseases: Hypoxia: Diagnosis - Measure dissolved oxygen levels
Treatment -Acute toxicity -Move fish to well oxygenated/aerated water
-Prophylactically -Aerate water-especially at night -Manage phytoplankton blooms -Reduce nitrogen in system
Non-Infectious Diseases:Hypercapnia:Clinical signs Narcosis Lethargy/depression Slowed respirationsDiagnosis Test water, pHTreatment Increase pH Increase oxygen Stop supplemental CO2
Non-Infectious Diseases:Gas-bubble disease: Nitrogen gas most commonClinical signs Gas bubbles under skin and fins, ischemia and necrosis Diagnosis Physical exam, evaluate water sourceTreatment Stop supplemental gas (CO2, pumps), evaluate water source (deep
well), minimize venturi’s .
Non-Infectious Diseases:
Avitaminoses
Vit. A deficiency – exopthalmia Vit. B1 deficiency – loss of balance Vit. B2 deficiency – photophobia Vit. D deficiency – lower haemoglobin Vit. E deficiency – anemia Vit. K deficiency – blood do not coagulate
Thank you for your attention