Goldfish are not prone to diseases, and are generally very hardy. Normally when fish are healthy and are not under stressed, it can resist disease with its own immune system similar to our human body. My best advise is not to focus on curing diseases but to prevent them. By paying attention to quarantine new goldfish before introduce to an established tank and prevent stressing the fish from overcrowded condition, poor water quality, poor nutrition, over feeding, two much medication or drastic temperature change. With the simple aquarium house keeping and proper feeding, there're really not much to worry about goldfish disease. Unfortunately, there may come a time when your goldfish does become sick. The following paragraphs should help you to identify, cure, or prevent the problem. These are the most common problems with fancy goldfish.
This problem is identified by large red blood vessels, red hemorrhage areas, and closed fins. Fin congestion is caused by poor water quality usually having high ammonia and nitrite levels in it. To treat this environmental disease make sure your filters are working properly, change your water more often, and reduce feeding until the water quality has improved,. Salt should be added at the rate of two to three tablespoons per five gallons of water. If secondary infections are present (fungus or bacteria), they should be treated with the appropriate medicine such as tetracycline.
Fin congestion causes scarring of the finnage and enlarged blood vessels. Once there they usually do not go away. The hemorrhages and frayed fins, if any, should disappear in four to six weeks if water quality has improved.
This infection is the most common and widespread parasitic disease among tropical and goldfish and is usually fatal if left untreated. Fish usually become susceptible to ick due to a chill, direct infection from a fish with a case of the disease or excessive ammonia buildup. Ick is a ciliated one-celled organism, Ichthyophthirius Multifiliis, which imbeds itself in the skin of the fish. The irritation causes small white blisters to form, appearing as white spots or nodules on the infected fishes' fins and body. Unless treated, the ick parasite multiplies rapidly and the body and fins of the host fish are soon covered. There are many effective ick medicine on the market. Just follow the instruction on the label. Usually the one that claim effective for cold water is better for treating fancy goldfish.
Ectoparasites which are tiny living creatures that suck fish blood or eat living flesh. They cannot transfer to other types of animals and will soon die when removed from water. These ectoparasites live on the skin, fins, gills and mouth cavity of the infected fish.
Some of the signs to look for are fish rubbing themselves on the bottom or scraping themselves against plants or ornaments. Red streaks on the fins may be an indication of hundreds of thousands of tiny transparent parasites swollen and red with the blood of the host fish. These parasites can weaken even the largest fish and may cause poor color, itching and even death.
The following are description of common type of external parasites found in goldfish. A broad spectrum parasitic medication are available in the market that will cure them all.
A crustacean and the head section is always embedded within living flesh and the long body (approximately 10 millimeter) hangs fully exposed.
Fish Louse (Argulus):
A 6 millimeter saucer shaped animal with two sucker discs and a poison stinger mounted between them. The sting can kill small fish. It sucks blood from the fish.
Gill flukes (Dactylogyrus):
A 0.5 millimeter monogenetic trematode that lives in the gills. Monogenetic refers to the ability of this animal to multiply without moving from the infected site. Lays eggs and sucks blood. Spreads easily.
Gill Mites (Ergasilus):
A 1 millimeter copepod that stays on the gills, feeding on blood and living flesh. Gill Mites cause fish to gasp at the surface and partially open gill covers.
Body flukes (Gyrodactylus):
A 0.5 millimeter monogenetic trematode that bears live young and spreads very quickly. Large colonies appear as red streaks on fins or bodies of goldfish because they suck blood into their transparent bodies.
For internal parasite where the symptom is that of a very thin fish, medicated feed is required for the cure and again those feed are available in the market.
A protozoan parasite. Blood spots, heavy slime coat, lack of appetite and activity, and cloudy clamped fins. Formalin, formalite or other protozoan treatment as directed can be used as a cure.
Velvet (Oodinium limneticum):
It is another protozoan parasite. This dinoflagellate attaches itself to the fish by its whip-like swimming organ and then grows more deeply into the fish. A cyst is formed on the skin and from it up to 200 new free-swimming parasites may be released.
At the beginning, this disease appears on the skin of the fish as a yellowish-brown film, usually near the dorsal fin. If untreated, it spreads quickly and develops into a series of small circular cysts having the appearance of a yellow velvety coat.
Of all the common ailments, velvet is the most difficult to diagnose and is often confused with ick or white spot, but the velvet granules are considerably smaller and more yellow than ick, an upon close inspection, you'll see they are gently moving. This disease is fatal to young fish and must be treated immediately. Adults often carry it without showing distress, but if they are used for breeding, the fry will succumb to the disease.
Fungus usually occurs as a secondary infection to bruises, attacks by other fish or an infection with some other organism which has weakened the fish or caused open sores on the body, which serve as an entry for fungus organisms. Fish are also made susceptible to fungus by sudden temperature changes, chill, overfeeding and poor water conditions.
The infected fish appear to have fuzzy white (Columnaris) or light gray (Saprolegnia) areas, which may be like a slimy surface or have a brush of filaments projecting from them. If not treated, the fungus may spread and destroy much of the tissue of the fish, resulting in death.
Tetracycline or commercial medication for fungus is readily available for the cure. Salt added to the water will help reduce fungus infections if your goldfish is injured. The progressive salt treatment can even be used as a treatment for fungus if commercial medications are unavailable.
Signs of these diseases very considerably. Mouth fungus looks like a cottony, fuzzy growth on the mouth. This very dangerous disease is actually a bacterial disease and responds well to a tetracycline bath.
General signs of bacterial infections are heavy body slime, lack of activity, clamped fins, red inflamed areas on body, fins, gills and head, frayed fins, and little or no appetite. For most goldfish external bacterial infection, tetracycline is about the best drug you can use. It is better to use antibiotics in a quarantine tank if possible, as they will kill your biological filters. For interior bacteria infections use commercial medicated food that contains the antibiotics. Lately, all natural extract from plant are available to cure most goldfish bacterial diseases without killing the beneficial bacteria in your biological filter. For example, Melafax.
This is a cold water bacterial disease that is very contagious. In the early stages small bumps will appear under the scales. As the disease progresses these bumps will enlarge and rupture forming large open sores. For best results any fish with open sores should be destroyed and buried deeply. All other fish should be treated with warm water (75 to 80 degree F), a tetracycline bath, and medicated food containing tetracycline. You may have to switch to another antibiotic if problem persist. Some strains of this disease have developed a resistance to tetracycline.
This disease makes the fish look very ugly; the bloated body of an Oranda for example with dropsey could look like Pearlscale with the scale protrude from the body. Dropsey can be caused by viruses, bacteria, or internal damage done by ammonia and nitrites. In most cases it is not curable. The fish should be disposed of quickly and humanely. A goldfish with dropsey sometime can last for a long time. The best way you could try is feeding the fish with medicated feed for 10 days and hope for the best.
Constipation is so easy to avoid it should never happen. Dry food is a main cause of this problem. If your goldfish eats too much dry food very quickly before it has had a chance to absorb enough water, it will absorb the water in the intestine which can cause an intestinal blockage.
Female goldfish full of eggs and in spawning condition are prompt to this condition, especially if they are too fat. They should be fed easily digested foods like duckweed, algae, chopped red worm, etc. to avoid this problem. Signs of this problem are lack of appetite, lack of activity, and swelling in the abdomen.
Signs of this problem are the inability of the goldfish to swim properly, with head-standing, floating upside down, sinking to the bottom, or floating at the waters' surface. Swimbladder problems can be caused by poor environmental conditions, improper food, obesity, genetics, bacterial and viral problems.
Genetic swimbladder problems are incurable. Bacterial swimbladder may respond to antibiotics medicated food. Virus problems are usually incurable. It is hard to tell the cause without performing advance analysis because the symptoms are the same.