Disease Recognition & Treatment

Daily observation of fish is important in the early recognition of disease. Changes in colour, swimming habit and behaviour can all serve as early warning signs of disease.

Ideally a sick fish should be isolated from tankmates in a separate aquarium. In reality, there are not many aquarists who have the facilities to do this. For this reason, most disease treatments take place in the display aquarium.

Common diseases of fish are usually caused by a parasite, fungus or bacterial infection. Fish can often be affected by a combination of these, for example, a bacterial infection is frequntly followed by a secondary fungal infection. Most common pathogens of aquarium fish are always present in the environment. It is when the fishes natural immunity is overwhelmed that these organisms are able to take hold. This could be due to poor water quality, rough handling, temperature fluctuations etc.

Standard fish medications are available which are effective against a range of common diseases. Antibiotics are also an option in serious cases. Common diseases of aquarium fish are listed below with some treatment options. (The medications suggested are to be used as per their individual instructions). Feel free to enquire about particular medications you don't see listed in the 'remedies section'.

FISH FUNGUS AND MOUTH 'FUNGUS'

Fungal diseases are commonly seen in fish that are in poor condition, particularly due to rough handling or physical injury. The brown or off white 'cotton wool' like growths are easily recognised as a fungal infection. Suitable treatments include malachite green, malkon, or methylene blue and salt in combination. Saprolegnia and Achyla are common fungal pathogens.

Flexibacter or mouth fungus as it is commonly called is actually a bacterial infection, although it is characterised by fungal like tufts around the mouth. Furan, a proprietary treatment containing furazolidone is effective against this disease.

WHITE SPOT

Small white pimple like growths on the fish is cased by the parasite Ichthyophthirius or 'white spot'. White spot is easily treated with a methylene blue preparation sold under the brand name of 'white spot cure'. White spot often follows a drop in temperature or the introduction of new fish. An immediate water change of at least 50% is essential to reduce reinfection.

GILL FLUKES

Gill flukes, a parasite of the gill membranes is most often found in goldfish and is particularly prevalent over the warmer months. Rapid gill movement and 'flicking' off rocks etc are indicative of this condition. Suitable treatments include formalin, malkon or acriflavine.

VELVET DISEASE

Velvet is caused by a skin and gill parasite, Oodinium, and causes a patchy 'velvet' like appearance in affected fish. Rapid gill movement and flicking off rocks etc are also characteristic. A malachite green and formalin combination is effective (malkon).

FIN ROT

Fin rot is a bacterial disease and is typified by ragged, split and blood streaked fins. Poor water quality is the main cause of this, particularly when the ammonia and nitrite levels are high. Various treatments are available to remove ammonia from the water. After remedying the cause, furan, acriflavine or malkon are effective.

NEON TETRA DISEASE

As the name suggests, this disease is most often found in neon tetras, although it does occasionally affect other tetras. The protozoan parasite Plistophora causes white opaque patches and the fish begins to waste away. There is no reliable treatment for this highly infectious disease, making immediate removal of affected fish necessary. Antibiotic treatment may be effective in some cases.

HOLE IN THE HEAD DISEASE

Discus and some other cichlids are the most likely to suffer from this disease caused by the protozoan parasite Hexamita. Inadequate nutrition or poor water quality are causative agents. Erosion of the head and flanks of affected fish are indicative of this disease. Furan tablets or antibiotic treatment from your vet is recommended.

OTHER PARASITIC INFECTIONS

Internal worms are not often seen in aquarium fish as they usually require the presence of another host to complete their life cycle. Pond fish sometimes suffer from infestations of fish lice and anchor worms. The use of a proprietary treatment is effective as well as physical removal of the larger parasites.

SWOLLEN EYES

Pop eye or exophthalmia causes one of both eyes to swell and protrude. There is no reliable treatment for this, however, the symptoms often diminish off their own accord. This condition does not appear to be contagious. Treatment with melafix may help.

GROWTHS AND TUMOURS

Large pond fish seem particularly prone to tumour like growths. As these growths are particularly difficult to treat and are not normally contagious, the fish are best left untreated.

SWIMBLADDER DISORDERS

Fancy goldfish are the most likely to suffer from this disorder as selective breeding has produced a body shape which frequently distorts the swim bladder. Affected fish typically float upside down and have an irregular swimming habit. There are no specific treatments available, however placement in a shallow bath of warm slightly salty water (3%) is sometimes effective. Symptoms will often subside untreated.

pH BURN

Symptoms are similar to fin rot but in this case are caused by a rapid change in pH, usually an increase in alkalinity. The addition of seashells, coral etc are often the cause. Immediate removal of this material as well as a partial water change will remedy the situation. Secondary infections are likely to follow.

HINTS FOR TREATMENT:

. Use test kits to anticipate disease causing conditions.

. Remove activated carbon while a course of medications is being undertaken.

. Excessive organic matter will reduce the effectiveness of most treatments.

. Some medications should be avoided in scaleless fish such as sharks and loaches   eg. malachite green, formalin, malkon.

. Before beginning treatment, change 50% of the water. This not only dilutes any harmful ammonia or nitrite but reduces the pathogen load of the water eg parasitic cysts, fungal spores etc.