Understanding Septicaemia in Aquarium Fish
Septicaemia in fish is a serious blood infection caused by bacteria such as Aeromonas, Pseudomonas and Vibrio. Common signs of septicaemia in fish include red streaks in fins, red patches or haemorrhages, swollen belly, bulging eyes, ulcers, clamped fins, lethargy, loss of appetite and difficulty swimming. If you suspect septicaemia, move the fish to a hospital tank, check and improve water quality (ammonia and nitrite must be zero), perform partial water changes, give a broad-spectrum antibacterial medication as directed, add aeration and keep stress to a minimum. Watch for reduced redness, return of appetite and better activity, but be aware that advanced cases may not recover and humane euthanasia can be kinder. To prevent septicaemia, keep water pristine, quarantine new fish for 2-4 weeks, treat wounds and infections early, avoid overcrowding and feed a balanced diet. Seek an aquatic veterinarian or experienced aquarium specialist if multiple fish are ill, fish decline rapidly or treatment does not work.