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

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