|
Regardless of how diligent one is, if you keep rainbowfishes long enough you will inevitably encounter a disease problem. When a disease problem develops, quick and effective response is essential. Many disease problems of rainbowfishes begin as external infections. If uncontrolled, the infections may become systemic, resulting in death of the fish. Correct use of chemical treatments can effectively control many bacterial, parasitic and fungal agents before systemic infections become established. In general, an experienced fish health professional should carry out treatment for all but the most common disease problems that your fish experience. However, even veterinarians with laboratory diagnostic experience cannot make an accurate diagnosis of some problems without microscopic examination of the fish or cultivation for bacteria.
Without professional assistance, any diagnosis is purely an educated guess based on yours or someone else's experience. This usually means that any medications or procedures used to attempt to cure the disease are chosen on the basis of the type of behaviour and physical appearance of the fish, as opposite to decisions made on the basis of diagnostic tests. In most cases a 'shotgun' approach using some medication or combination of medications will be used. The downside of this idea is that in most situations the majority of the chemicals given to the sick fish are useless in terms of efficacy, since they are not targeted at the desired pathogens.
Experienced aquarium hobbyists can and do make accurate, presumptive diagnosis's based on examination and assessment of the clinical signs, and then apply affirmative control measures. Nevertheless, if abnormal behaviour persists and/or mortalities occur, then you should seek professional assistance. However, the cost of treatment may exceed the value of the fish in the aquarium or pond. An aquarist with a large-scale breeding set-up stocked with valuable, rare or endangered fish, for example, would probably be wise to spend the money on proper diagnose. On the other hand, if the loss only involved common species, then spending a lot of money for a fish health professional may not be economically sensible. Therefore, economics and other factors will determine the appropriateness of treatment.
Following any disease outbreak, infected fish should be immediately removed from the main aquarium and isolated in a quarantine or treatment tank. Infected fish can shed pathogens, even when they show no signs of diseases, but especially when they are either morbid or dead. Pathogens tend to leave dying and newly dead fish as they are no longer any use as hosts! However, it is acknowledged that this is not always possible. If treatment is undertaken in the main aquarium, a large water change (50~75%) together with thorough gravel cleaning in order to remove excess waste (faeces, uneaten food, detritus, etc.) from the substrate should be undertaken. This includes the removal of algae from tank walls and particulate matter from the filter (change filter wool or wash sponge etc.).
Most aquarium medications are affected by variations in water chemistry such as pH, carbonates, chlorides and dissolved or particulate matter. In water that is high in dissolved organic wastes the chemicals will oxidise the wastes rather than attacking the disease causing agents. This has the effect of lowering the effectiveness of the chemical dosage. Failing to ameliorate water conditions while treating sick fish with medication will usually either prevent the medication from being effective or will cause the disease to recur after the treatment is completed. Most chemicals used to treat fish diseases can be toxic to nitrifying bacteria at therapeutic levels for fish. Antibiotics are generally toxic and have a severe detrimental effect on nitrifying bacteria. Therefore, it is advisable to take biofilters off-line during treatment and to do a large (75%) waterchange prior to re-establishing the filtration system.
© Copyright Adrian R. Tappin
Created July, 2005
Updated December, 2008
|
|
