This is one of the most dangerous fish diseases which is difficult to treat in advanced stage. Their symptoms are difficult to diagnose or they are similar to symptoms of other illness. This disease is caused for gram-negative bacteria which commonly are in each reservoir - they live and feed dead organic matter (food remains, parts of plants). They can unlimited expand and reproduce in favourable conditions (e.g. water temperature above 15°C, hard water, pH=6.5-10). Then these bacteria attack weakened fish (with weakened immune system from different causes). The bacteria attack the fish through mouth, gills, wounds, they can develop also from the interior of the body. They release toxic enzymes which gradually degrade the cartilage.
Changes appear on the fish skin as round or oval, pale area, without shine in initial stage of the disease. Progression of the disease (death of the fish within a few hours or several days) depends on aggressiveness of the bacterial strain, attacked body part and environment (optimal conditions for reproduction). Open wounds appear on the skin, the fish swims under the water surface in advanced stage of the disease and it lies on its side on the aquarium bottom just before its death. Disease mortality and aggression of the bacteria increase when the gills will attack.
The optimal conditions for the bacteria: rapid changes in water temperature (mostly its increase), increase nitrates level, alkalinization of the water, increase water hardness, oxygen-poor water, slow water flow. Infection by Aeromonas bacteria favours infection by described bacteria.
Increase water temperature doesn't hasten of treatment in this case, on the contrary – it favors of the bacteria reproduction. This disease is caused by neglect of cleanliness in aquarium. We need do 30-50% water change and precisely cleaning of the aquarium bottom before treatment starting. We need also find and eliminate a direct cause of this disease, so we need do necessary water tests. We do partial water changes in the general tank every day.
We do a selected treatment in a separate aquarium. The fish with advanced symptoms we can't cure, so we should immediately commit an act of euthanasia them.
We may add 2 tablespoon per every 10 litres of the water at the general tank after each partial water change. We do the curative bath in a separate aquarium and we add 20-30g of the salt per every litre of the water. This is short-term bath and it should last 5-20 minutes. We must observe the fish all the time. We must end the bath when a fish turns on its side. Then we transfer the fish to the general tank and we leave it until next bath. We do these baths a few times per day for minimum 7 days or until resolution of symptoms. There may occur extra discolorations on the fish skin but we shouldn't worry about them.
First day: we dose 22 drops or 1 ml of the preparation per every 20 l, second day: pause, third day: we dose 22 drops or 1 ml of the preparation per every 20 l. We need remove the active carbon from the filter and increase oxygen saturation during the treatment.
We dose 10-20mg per every litre of the water. We may repeat the dose for 2 days. We need remove the active carbon from the filter during the treatment.
We dose 10 000 units per every litre of the water. We may repeat the dose for 2 days. We need remove the active carbon from the filter during the treatment.
We dose 10 mg per every litre of the water for 7 days.
We add this drug to a food and we dose 0.03 g per every gram of fish weight.
Other effective antibiotics: streptomycin, oxytetracycline, erythromycin.
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