AQUARIUM FISH DISEASE TREATMENT



DISEASES

Under ideal circumstances-proper water conditions, a varied diet, uncrowded conditions, and a stress-free environment-diseases rarely affect fish. Typically, fish become ill when environmental conditions deteriorate or when new fish introduce pathogens into the tank. Healthy fish have strong immune systems that can resist most diseases, but stress weakens their defenses, making them more susceptible. Several factors, both non-living and living, contribute to fish stress.

NON-LIVING SOURCES OF STRESS

Non-living stressors include poisoning, incorrect temperature or pH, and insufficient oxygen.

    Ammonia Poisoning
    Ammonia poisoning occurs due to the accumulation of organic waste from overfeeding, decaying plants or fish, and improper tank cycling. It is especially dangerous in alkaline water (pH >7), where non-toxic ammonium converts into toxic ammonia. Symptoms include sluggishness, panting, gill discoloration (gill burn), and fish hovering near the water surface. To remedy ammonia poisoning, reduce feedings, perform water changes, lower the pH, use zeolites, and increase aeration.

    Nitrite/Nitrate Poisoning
    Nitrite and nitrate poisoning result from the same causes as ammonia poisoning. Symptoms are similar, and the condition can be confirmed with a nitrite/nitrate test kit. Treatment involves reducing feeding, performing frequent partial water changes, and increasing aeration.

    Chlorine Poisoning
    Chlorine, commonly found in tap water, is highly toxic to fish, affecting the gills and leading to asphyxiation. Chlorine can be removed by boiling the water, letting it stand for several days, vigorous aeration, or using a water conditioner.

    Heavy Metal Poisoning
    Heavy metals, often introduced through old pipes or metal objects in the tank, can be toxic to fish. Symptoms include rapid breathing and gasping at the surface. Heavy metals can be removed with a reverse osmosis system, activated carbon filtration, or water conditioners.

    Hydrogen Sulfide Poisoning
    Hydrogen sulfide, a toxic gas with a rotten egg-like odor, forms in anaerobic pockets within the substrate due to decaying waste. Affected fish gasp at the surface. To resolve this, perform large water changes while siphoning the substrate. Repeat partial water changes until the odor disappears and fish recover.

    Medication Poisoning
    Improper use of medications can harm fish, particularly sensitive species such as catfish, tetras, Mormyrids, and loaches. Copper-based medications are toxic to invertebrates and should not be used in tanks containing snails or crustaceans. Always follow dosage instructions. If adverse effects occur, perform a partial water change and use activated carbon to remove the medication.

    Other Pollutant Poisoning
    Household chemicals such as cigarette smoke, paint fumes, and pesticides can contaminate tank water. Preventing exposure is the best defense. If contamination occurs, perform water changes and use activated carbon filtration.

    Incorrect Temperature
    Tropical fish thrive within specific temperature ranges. Sudden fluctuations can weaken them, making them susceptible to disease. To prevent this, use a reliable heater and place the tank away from drafts.

    Incorrect pH
    Most tropical fish require a stable pH. A drastic pH shift can cause stress, leading to darting movements, inflamed gills, rapid breathing, and gasping at the surface. If pH is too high or low, gradually adjust it using buffers. Regular pH testing helps prevent imbalances.

    Oxygen Shortage
    Signs of low oxygen levels include rapid gill movement, fish gathering near the surface, loss of color, and eventual death. Causes include poor aeration, excess organic waste, high temperatures, and plant respiration at night. To correct oxygen depletion, perform a partial water change, increase aeration, and remove decaying matter.
LIVING SOURCES OF STRESS

Living stressors include pathogens such as parasites, bacteria, fungi, and viruses. These organisms thrive when fish are weakened by stress or when an infected fish is introduced. Aggressive tank mates can also cause stress. Below are common diseases affecting tropical freshwater fish.

COMMON PARASITES AND DISEASES AFFLICTING TROPICAL FRESHWATER SPECIES
    PARASITES
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    Velvet Disease (Oodinium)
    Symptoms: Fine gold-to-gray film covering the body, gill flaring, gasping, and rubbing against objects.
    Treatment: Raise the water temperature to 88-93�F (31-34�C), turn off lights, and treat with copper sulfate, Trypaflavine, methylene blue, a malachite green-formalin combination, or Quinine Hydrochloride. A salt bath is an alternative treatment.

    White Spot Disease (Ich, Ichthyophthirius)
    Symptoms: White spots on the body and fins, gray slime patches, emaciation, scratching against objects.
    Treatment: Increase the temperature to 86�F (30�C). Use malachite green-formalin, Trypaflavine, Quinine, or aquarium salt. Treat for at least three weeks to eliminate all parasite life stages.

    Gill Flukes (Dactylogyrus, Cichlidogyrus, Tetraonchus)
    Symptoms: Slimy gills, rapid breathing, panting at the surface, emaciation.
    Treatment: Treat with Droncit (Praziquantel) at 2 ppm or malachite green-formalin. Flukes lay resistant eggs, requiring multiple treatments.

    Fish Lice (Argulus)
    Symptoms: Red, inflamed spots, scratching, visible lice on the skin.
    Treatment: Manually remove lice with tweezers. If infestation is severe, raise the temperature to 86�F (30�C) and treat with dylox, masoten, or trichlorfon. Remove invertebrates before treatment.

    FUNGAL DISEASES
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    Saprolegnia and Achlya
    Symptoms: Cotton-like tufts of fungus on the body, which may turn brown.
    Treatment: Raise the water temperature. Treatments include a 30-minute sodium permanganate bath (1 ppm), malachite green, or commercial antifungal medications.

    BACTERIAL INFECTIONS
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    Fish Tuberculosis (Mycobacterium)
    Symptoms: Loss of color, appetite, hollow-bellied appearance, spinal deformities, ulcerations, and pop-eye.
    Treatment: Highly contagious. Infected fish should be euthanized. Some success has been reported with antibiotics (Oxytetracycline, Kanamycin). This disease is transmissible to humans-handle infected fish with care.

    Dropsy (Aeromonas, Pseudomonas)
    Symptoms: Swollen body, protruding scales, bulging eyes, pale gills, red patches on skin.
    Treatment: Usually fatal. Isolate infected fish and attempt antibiotic treatment.

    Fin Rot (Pseudomonas and others)
    Symptoms: Frayed, discolored fins that deteriorate over time.
    Treatment: Caused by poor water conditions. Treat with Trypaflavine baths or commercial medications.

    Neon Disease (Sporozoasis)
    Symptoms: Loss of color, erratic swimming, emaciation, opaque skin.
    Treatment: Incurable. Infected fish should be euthanized to prevent spreading. Disinfect the tank.

    Discus Plague
    Symptoms: White patches, fin disintegration, excess mucus, fish turning dark, huddling.
    Treatment: Maintain a low pH (4-5), perform daily water changes, and avoid feeding. Potassium permanganate may reduce bacteria.