Tumours

Tumours can be caused by a virus or a cancer, but most tumours are genetic. The genetic tumours may be caused from too much hybridization, common amongst professional breeders. Practically all tumours are untreatable. If the fish is in distress, it should be destroyed.

Congenital Abnormalities

Abnormalities usually occur when professional breeders are trying to acquire certain strains in breeds. Most are beneficial abnormalities like albinism or extra finnage. But undesirable abnormalities crop up and are usually culled out by the breeder. However, such abnormalities sometimes happen in the amateur aquarium. If the abnormality is not life threatening or degrades the quality of life, just leave it be and brag to your friends about the unusual inhabitant. Otherwise, the fish should be humanely destroyed.

Injuries

Even in the best of aquariums and under the supervision of the most astute aquarists, injuries occur. Some times a bully fish is the culprit, or sharp decor. Sometimes there appears to be no explanation. As in the human world, accidents happen. If the cause of the injury is obvious, it should be remedied. Then the injury should be treated. The injury should be touched with 2% Mercurochrome, which is supplied commercially. Also, depending on the fish's tolerance to water conditions, keeping the fish in slightly acid water should speed recovery (pH 6.6). Minor injuries, if the water conditions are good, should just heal themselves.

Constipation

Some fish are more susceptible to constipation than others. Usually fish with more compressed bodies like angelfish and silver dollars. Symptoms are loss of appetite and swelling of the body. The cause is almost always diet. Usually, with a change of diet, the condition rights itself. But in stubborn cases try dried food that has been soaked in medicinal paraffin oil. Glycerol or castor oil may also be used. If the diet is changed on a regular basis and live foods offered occasionally this condition may never occur.