FURUNCULES
Furunculosis is a very serious fish disease characterized by high mortality. The disease is caused by a bacilliform bacterium called Aeromonas salmonicida. The bacteria do not form spores and do not have flagella. At water temperatures between 10 and 20° C, the bacteria multiply successfully and remain active up to 3° C.
Carp fish are most susceptible to furunculosis. And usually infected by adult fish over 2 years of age, juveniles do not usually fall ill.
Considering the fact that the furunculosis bacteria are mainly active in a limited temperature range, the infection usually peaks in spring and summer months. At temperatures of 15-20°C, the bacteria incubate for 7-8 days. When the temperature drops below 7°C, the disease goes dormant, but as soon as the water temperature rises slightly, it flares up again.
An infected fish stock, dead fish, waste products and poor quality live food can provoke the disease.
Diagnosis
The disease has an acute course, but there are hardly any symptoms at the infection stage - the fish become ill overnight, and just as quickly die. The fish become inactive, stay near the water surface and do not eat at all.
Their scales and gills are covered with blood, and blood clots can be seen in the waste products. Death occurs within 2-3 days if the disease is acute.
The subacute course of the disease is characterized by the furuncles penetrating into the muscular region. The fish develop exophthalmos. This stage of the disease lasts 4-7 days, with a very high mortality probability.
If the disease becomes chronic, the fish gradually lose their scales, the colour darkens, the fins decay and deteriorate completely, and the fish become dystrophic. This form of the disease takes a long time and can sometimes last 4-6 months.
The disease can only be accurately diagnosed by performing bacteriological tests in the laboratory. Blood and skin samples are taken from different parts of the infected fish. Such measures are difficult and unnecessary at home. The disease is usually diagnosed under these conditions by external signs.
Treatment
Treat fish sick with boils, sulfonamides and antibiotics that are mixed into the feed. Terramycin, chloramphenicol and levomycetin can achieve good results.
You need 0.05-0.07 g of these treatments per 1 kg of fish. Treat for 2-3 weeks or until healed. The quarantine tank with the infected fish should be darkened for the duration of the treatment. The aquarium should only contain fish, no decoration, plants or substrate should be. Strong aeration of the water is also required.
