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All about Aquarium Fish Diseases: The best Preventions and Treatments

Aquarium fish keeping is a relaxing hobby as long as your finned friends can thrive in the water. Fishes like humans are vulnerable to diseases. Identifying diseases in fish requires an attentive eye, as symptoms may remain undetected until becoming a life-threatening disease. As an aquarium owner, understanding these common illnesses and symptoms may help save your fish’s life. Here is a guide that will help you prepare for swift action in case your pet fish contracts any disease, or better still help you prevent such diseases in the first place.

Parasitic Diseases in Aquarium Fish

Ich (white spot disease): one of the most common parasites in aquariums is Ichthyophthirius Multifiliis also known as Ich. If your fish has contracted Ich, it will develop small white spots on its body, fins, and gills. As a result, the fish may rub themselves against the decorations, twitch, or dart in the aquarium. If the parasites reach the gills they may further exhibit labored breathing. All fishes are susceptible to Ich, but scaleless fishes such as loaches, catfishes, eels, silver dollars, hatchet fish, and bala sharks may be more prone. As Ich is highly contagious, you must treat the entire aquarium. You must begin by raising water temperatures to 28-30°C, which will speed up the parasite’s life cycle and make the medication work. Copper-based treatments, malachite green, and salt baths can kill the parasite.

Velvet (gold dust disease): it is caused by the protozoan parasite Piscinoodinium which penetrates the fish skin and feeds on it. This will cause your fish to develop a dusty golden or rusty coating on their bodies. This parasite attacks the gills first, before spreading to the rest of the body. If the yellow dusty spots are visible on your fish’s body, it’s an indicator that the infection is already severe. Other symptoms include clamped fins and lethargy of the fish. Freshwater fish and marine tropical fish are at equal risk of this parasite. As this disease is only identifiable at advanced stages, immediate treatments need to be established. Treatments are similar to Ich disease, along with dimming lights to lower the growth of this light-dependent parasite.

Anchor Worms: parasitic crustaceans called Lernaea Cyprinacea also known as anchor worms are worm-like parasites that attach themselves to the fish. These parasites are known to embed themselves on the skin and burrow into the muscles of the fish. Effected fish rub against objects, and have a whitish green thread like protrudes stuck onto their scales. At the point where these anchor worms connect, are inflamed which increases the chances of secondary infection. This disease can affect any fish but is usually seen affecting goldfish and koi. You need to physically remove these anchor worms using sterilized tweezers and dress the affected area with antibacterial medications. The aquarium also must be treated with salt, Dimlin, or Potassium permanganate to kill any larvae of the parasite.

Bacterial infections and their management

Fin Rot: bacterial infections from the bacteria Aeromonas or Pseudomona can swell the base of fins causing fraying of the fins. These ragged fins become discolored and can deteriorate to the extent that they may fall off if left untreated. Fin rot is initiated by the poor quality of water and aggravated by fin nipping or bullying attitudes of other fish in the tank. Fin rot can appear in all fishes. Treatment begins with regular water changes, followed by the use of antibacterial medications like erythromycin. Infected fish must be quarantined to prevent further spread of infection.

Dropsy (edema): a bacterial infection that leads to the swelling of fish bellies and scales protruding resembling pinecones. This infection affects the kidneys, leading to renal failure and fluid retention in fish. You can see the fish having difficulty in swimming. This disease may stem from unclean aquarium conditions and is difficult to treat. Antibiotics like kanamycin or tetracycline, along with Epsom salt baths may relieve the fish and reduce water retention.

Columnaris (cotton mouth): the bacterium Flavobacterium columnare causes fish to develop white cotton-like lesions at the opening of their mouth. These lesions can appear on the body and fins too. This makes it difficult for the fish to breathe and creates lethargy. At advanced stages of the disease, the fish may have ulcers, fin erosion, and rapid death. This infection is best treated with injectable antibiotics like kanamycin or furan-based medications. You can also reduce the water temperature to slow down the spread of bacteria, as they thrive in warmer conditions.

Fish

Fungal diseases and their cures

Saprolegniasis (Cotton Wool Disease): the fungi Saprolegnia causes fish to have white fluffy cotton-like growth on their skin. This disease is an after effect of an earlier infection and is seen at the site of previous injury. All fish are equally exposed to the risk of this disease. Treatment begins with isolating the infected fish and cleaning the aquarium with antifungal medicines like methylene blue or aquarium salt. You must take care of the quality of water in the aquarium to prevent recurrence.

Egg Fungus: fungal spores like Saprolegnia can directly affect the eggs of the fish, killing them. This fungal growth is seen on top of the eggs, in the form of white cottony threads. This fungal growth is triggered by poor water conditions. There is no treatment for affected eggs, the remaining or new eggs must be treated with antifungal agents like methylene blue. Good water circulation around the eggs can prevent this disease altogether.

Preventative measures to keep fish healthy

Prevention is better than cure, this is also appropriate when keeping your finned friends healthy. By regularly cleaning the aquarium, the filters, and equipment you can prevent diseases from spreading initially. Similarly, maintaining correct pH levels of water and regularly checking for ammonia, and nitrate levels are key.  New fishes should be isolated for at least a month to prevent foreign objects from entering your main aquarium. Most importantly, avoid overcrowding the tank as it may induce stress on the fish and create bullying behaviors amongst themselves. Infected fish, on the contrary, must be immediately quarantined and medicines must be provided in recommended dosages to cure them.

Conclusion

Early detection of fish illnesses is important as it allows for prompt treatment, increasing the chances of recovery. Fish often hide signs of sickness until the disease is well advanced, so it’s essential to regularly monitor their behavior, appetite, and appearance. Stress, poor water quality, and the introduction of new fish can lead to various infections and diseases. By creating an optimal environment and staying vigilant, you can significantly reduce the risk of disease in your aquarium.

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