Fin Rot

Fin rot is a general term for necrotic loss of fin tissue, resulting in split or ragged fins. It is usually the edge of the fin that is attacked, although occasionally a hole may appear in the middle of the fin. The appearance of fin rot can vary between a distinct, semi-circular “bite” shape and a “shredded” effect.

The edge of the lesion is usually opaque or whitish. In advanced cases there may be some reddening or inflammation. The main threat from this fish disease is, if left untreated fin rot can slowly eat away the entire fin along with the fin rays and start to invade the fish’s body, leading to peduncle disease if the caudal (tail) fin is involved, or saddleback ulcer if the dorsal (top) fin is affected. Fin rot is a bacterial disease involving opportunistic bacteria such as Aeromonas, Pseudomonas orFlexibacter that abound in all aquatic environments. Secondary fungal infections are not uncommon.

Usually caused by stress

With very few exceptions, virtually all cases  are precipitated by stress, fear or poor environmental conditions. Indeed, fin rot is often one of the first signs that a fish disease problem exists and all cases should be investigated to determine the underlying cause. When I have fish in for hospitalization, occasionally some sensitive fish will start to develop fin rot as a consequence of their strange new surroundings and being handled – even though they are being kept in optimum conditions. It is usually self-resolving as they settle in, but does demonstrate just how sensitive fish can be to stress and how fin erosion is often a sign that all is not well.

Used with express permission from fishdoc.co.uk

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