Hemorrhagic Septicemia in a Goldfish

Goldfish are susceptible to a wide range of bacterial pathogens, including aeromonas that cause hemorrhagic septicemia in these cold water fish. Aeromonas micro-organisms enter the fish's blood stream, causing septic shock, which is invariably followed by death of the fish. The first signs of hemorrhagic septicemia are red streaks that are soon followed by skin lesions. These legions are initially superficial, but become much deeper and progress to ulcerations and the destruction of underlying muscles.

  1. Causes

    • Hemorrhagic septicaemia is often a result of stress or overcrowding. This disease transmits via both diseased fish and contaminated water and can kill large numbers of fish in the confines of a small, poorly managed aquarium or pond. Ammonia spikes will also lower the fish's immune system to the point that the aeromonas bacteria can get a foothold on its system. Once the immune system is impaired through stress, the goldfish is unable to protect itself against these and other species of destructive micro-organisms.

    Clinical Signs

    • Goldfish suffering from hemorrhagic septicaemia exhibit a swollen and hemorrhagic vent, together with ulceration over different areas of the creature's body. These lesions quickly develop into open wounds which destroy the fish's skin and underlying tissues, including the muscles. Exophthalmus, which refers to the protrusion of one or both eyeballs, may occur. Fluid normally accumulates in the abdomen and purple or red spots are also visible on the fish's body. The fish's mouth and fins will also hemorrhage and the skin becomes discolored. As the disease progresses, it eventually destroys the goldfish's heart, kidneys and liver.

    Diagnosis

    • A diagnosis is confirmed by culturing the disease organism from goldfish which are infected. If the condition is due to the presence of ammonia in the water, the goldfish will exhibit hyperventilation, or excessively rapid breathing. These fish will also gasp at the water surface and swim in an erratic manner.

    Treatment

    • Goldfish are heavy bodied fish that produce large amounts of metabolic waste, including ammonia. These fish require powerful filters that incorporate mechanical, chemical and biological filtration. Ensure that aquariums or ponds in which goldfish are housed are well oxygenated and rinse or replace dirty filter material on a regular basis. Broad-spectrum antibiotics are most successful in treating hemorrhagic septicaemia. Place diseased fish in a hospital tank for treatment, as antibiotics will destroy the beneficial bacteria in the filters of the display pond or aquarium.