Saprolegniasis

Saprolegniasis is a disease of the epidermis of fish. It typically starts on the fins or head and often spreads over the entire body, being visible as white or grey mycelial patches. Spores commonly enter the fish body via damaged gills. In Salmonids, saprolegniasis is associated with stress.

Branchiomycosis - Gill Rot

Branchiomycosis is an acute infection of the gills that can cause high mortality and respiratory distress in many species of ornamental and freshwater fish such as the Koi, the eel, the bass and the perch. 

Branchiomycosis affects the fish's gills by causing them to become mottled, or blotchy in appearance due to the dying tissue. For this reason it is also known as "gill rot." There may also be traces of gray on the surface of the skin.

Icthyophonus Disease

External symptomatic features of I. hoferi infection in fish are not specific; spiralling, whirling and spinal curvature have been reported. Internally a whitish speckling and the presence of raised nodules on the muscle and internal organs resulting from an inflammatory response to the fungus are common features.

Epizootic Ulcerative Syndrome (EUS)

EUS causes ugly lesions in affected fish. Lesions can range from small pinpoint red spots, haemorrhagic spots, localized swelling, localized raised areas on the body surface, protruding scales, scale loss, skin erosion, reddened areas of the skin under the scales, exposure of underlying musculature, and ulceration.