Goldfish Diseases: Symptoms, Causes, and Treatments

Prevention:

Preventing disease is the best way to keep your goldfish healthy. While prevention isn't always foolproof, it greatly increases the chances of maintaining healthy fish.

• The first step to disease prevention is selecting only the highest quality fish. When choosing a new goldfish, aim for high standards. If the aquarium store has dirty tanks with sickly fish, your new fish may not thrive. But if the tanks are clean and the fish look robust and healthy, your goldfish is more likely to stay healthy as long as you care for it properly after purchase.
• The second step is keeping the aquarium water in top condition. Goldfish produce a lot of waste and are quite sensitive to dirty water. It’s crucial to provide good filtration and perform regular partial water changes. Avoid overfeeding, as goldfish have short digestive tracts and no stomachs, which means they absorb less of the food and excrete most of it as waste. This waste increases ammonia levels in the water quickly, leading to various health issues. Regular water changes and good filtration can prevent most health problems.
• Adding a small amount of aquarium salt to the tank can help prevent some common goldfish diseases. For example, Ich and fungus are less likely to develop if there's a trace of salt in the water. The key is to keep the salt levels low so you can add more if needed during an outbreak. Be careful not to add too much salt because goldfish aren't saltwater fish and can only tolerate small amounts of salinity.

Medication and Chemicals:

Medication and chemicals should never be used as a preventative measure for goldfish or any fish. It’s essential to limit the use of medications in your aquarium. Only use medicine when absolutely necessary to ensure it works effectively when needed. If medications are constantly present, certain diseases may develop resistance, making the medicine ineffective. Below, you’ll find the proper medications and treatments for each goldfish disease.

What Not to Do:

Knowing the common diseases and conditions goldfish can suffer from will help you care for your fish better. However, there are a few things that aquarists often overlook when dealing with sick fish. Here’s a list of things to avoid.

• Don’t add new fish to the aquarium until your current fish are disease-free and stress-free. Avoid overcrowding the aquarium, as this can lead to many problems, including increased stress, waste, and higher levels of chemicals like ammonia, nitrite, and nitrate.
• Don’t use multiple medications unless they specifically state that they are safe to use together. Usually, medications from the same brand can be used simultaneously.
• Don’t perform too many full water changes or move your fish around, except when moving a sick fish to a hospital tank. Disturbing the tank too much can stress the fish, making it harder for them to recover. As much as possible, stick to partial water changes to keep water conditions optimal.

Diseases/Conditions and Their Treatments:

• Ich

  Ich, also known as ick, is short for Ichthyophthirius multifiliis, one of the most common diseases affecting fish. It manifests as small white spots resembling grains of salt on the skin and gills. This disease often occurs when fish are under stress or when new fish are introduced into the aquarium. The initial treatment involves raising the water temperature and adding a small amount of salt to the tank. However, be cautious with this approach, as not all species can tolerate salt. For instance, Loaches, corys, snails, and certain aquatic plants are particularly sensitive and may not survive if the salt concentration is too high. If these measures fail, consider using medications that contain copper.

• Fungus

  Fungus commonly develops at the site of wounds or sores, resembling a small ball of cotton around the affected area. This fungal growth is often a result of bacterial infection. To treat this condition, you can use an antibiotic such as Maracyn, which is effective against bacterial infections and helps eliminate the fungus.

• Swim Bladder Disorder

  Swim bladder disorder is a common issue among fancy goldfish, particularly those with shorter, rounder bodies. This condition arises because their swim bladders develop differently due to their unique shapes. Goldfish are selectively bred for their rounded bodies and pronounced hunchbacks, which often causes their organs, including the swim bladder, to be positioned abnormally. The swim bladder is responsible for maintaining a fish’s balance, allowing it to swim normally. If the swim bladder isn't functioning correctly, it can cause significant stress to the fish and may eventually lead to death. Performing a complete water change could be the most effective solution, as studies suggest that a nitrate-free environment can help cure swim bladder disorder.

• Gasping at the Surface

  If your fish is gasping at the surface or showing signs of labored breathing, it may not be getting enough oxygen. This can occur due to high water temperatures, increased salinity, or elevated levels of chemicals or medications, all of which can reduce oxygen levels in the water. In this case, these treatments are not recommended. First, check if your filtration system is functioning properly. Also, ensure that there is no oil or scum on the water's surface, as gas exchange occurs there, allowing fish to get oxygen. It's crucial to have some surface agitation to facilitate this exchange. If you notice any oil or scum, remove it immediately by scooping water from the surface until the gunk is gone. Ensuring ample surface area with sufficient agitation or water movement is vital for oxygen to enter the water effectively.

• Constipation

  Constipation is a common issue for goldfish, but it's easy to address. Unlike many other fish, goldfish lack stomachs to aid in digestion, relying instead on short digestive tracts that quickly process their food. Because of this, it’s essential to feed them easily digestible foods designed specifically for goldfish, allowing them to absorb the necessary nutrients efficiently. If a goldfish becomes constipated, it can lead to other issues, such as swim bladder disorder, so prompt action is crucial. Signs of constipation include lethargy and a swollen appearance. If you notice these symptoms, stop feeding regular flake or pellet food for a few days and offer vegetables instead. Just like humans, fish benefit from a balanced diet. Softened spinach, peas, or lettuce leaves are good options for relieving constipation. When you resume feeding flakes or pellets, soak the food in water beforehand to make it easier for your goldfish to digest.

• Fin and Tail Rot

  Fin and tail rot often result from stress caused by poor water conditions, overcrowding, or rough handling by humans or other fish. This condition is easy to identify, as the goldfish’s fins and tail appear shredded or begin to rot away. Fin and tail rot is caused by various bacteria present in the water. The first step in treating this condition is to perform a partial water change, followed by adding antibiotics like Maracyn 2 to eliminate the bacteria. To help heal the damaged fins, you can use a medication called Melafix, which is commonly used by aquarists to treat wounds and promote fin repair.

• Pop Eye

  Pop Eye is a condition rather than a disease, and it is identified by the protrusion of the eyeball from its socket. This condition can be triggered by several factors, including poor water quality, bacterial infection, or injury caused by other fish. The swelling and fluid retention behind the eye are what cause it to bulge. To treat Pop Eye, first, move the affected goldfish to a hospital tank with clean, well-aerated water, but without an activated carbon filter. Sometimes, these steps alone can reduce the swelling and infection. If the condition persists, treat the fish with Tetracycline, a broad-spectrum antibiotic effective against bacterial infections.

• Dropsy

  Dropsy is a condition characterized by noticeable swelling of the abdomen, which causes the fish's scales to protrude from its body. This swelling results from fluid accumulation in the abdominal area, often making the goldfish lethargic and disinterested in food. The disease may be caused by bacteria or contaminated food, and in such cases, treatment with a broad-spectrum antibiotic can be effective. However, if Dropsy is due to kidney, liver, or heart failure, it cannot be treated with medication.

• Hole in the Head Disease

  Hole in the Head Disease affects goldfish as well as other freshwater fish. While the exact cause is not known, it is believed to be linked to factors such as bacteria, parasites, nutrient deficiencies, or poor water quality. This progressive condition develops over time, initially presenting as small holes on the fish's head, which may then secrete mucus and cause the fish’s protective slime coating to deteriorate. Early detection offers the best chance of recovery. Begin treatment by isolating the affected goldfish in a hospital tank with fresh, clean water. A water conditioner like Stress Coat, which contains Aloe Vera, can help promote healing and replenish the slime coat. Ensure the fish receives a well-balanced diet with essential vitamins and nutrients. Adding a small amount of salt to the tank may also aid in halting the disease’s progression. If these measures are insufficient, a last resort treatment is Metronidazole, which targets specific bacteria and parasites associated with the disease, although its effectiveness is not definitively proven.

• Costia

  Costia is a disease caused by rapidly moving parasites. It presents as milky slime patches on the skin of infected goldfish, and the fish may also experience breathing difficulties. If left untreated, Costia can be fatal. To treat this condition, first raise the aquarium temperature to between 80 - 83°F (approximately 27 - 28°C). Then, use a suitable medication. Two effective options are Copper Safe and Acriflavine. Copper Safe is effective but can be toxic to certain fish species, so check the label carefully to ensure it is safe for your tank. Acriflavine is another effective treatment, but it may cause sterility in fish, which could make it unsuitable for your aquarium.

• Trichodina

  Trichodina is a parasite that attaches itself to the skin and gills of goldfish and other freshwater fish, causing irritation and itching. Affected fish may be seen scratching against surfaces, which can lead to ulcers and additional stress. This condition often arises from poor water quality with high bacteria levels, as Trichodina feeds on these bacteria. Improving water quality is crucial for managing this issue. While salt can be effective, some strains of Trichodina have developed resistance to salinity. In such cases, use Quick Cure as directed to effectively treat the infection.

• Velvet

  Velvet is a parasitic infection affecting both freshwater and saltwater fish. Often referred to as Gold Dust Disease due to its distinctive gold, dust-like appearance, it gives the fish's skin a velvety texture. Infected fish may exhibit signs such as scratching against surfaces, difficulty breathing, and lethargy. To treat velvet, start with a partial water change and ensure the water is clean. Dim the aquarium lighting and add a small amount of aquarium salt, which can help resolve mild cases if addressed promptly. For more severe infections, use medications like Quick Cure or Copper Safe to thoroughly eliminate the parasite.

• Body and Gill Flukes

  Body and gill flukes, also known as Shimmies, are parasitic worms that infect either the body or the gills of goldfish, or both. Gill flukes and body flukes differ in their reproduction methods; gill flukes lay eggs in the substrate, while body flukes give birth to live young. This difference makes gill flukes more challenging to eradicate. Symptoms of infestation include scratching against surfaces, a thickened slime coat, breathing difficulties, and lethargy. Treatment options include Potassium Permanganate, which is effective but can be costly, and Quick Cure, which may be less effective. Repeat treatments at least twice after the initial application to ensure all gill fluke eggs are destroyed and prevent recurrence.

• Anchor Worm

  Anchor worm is a highly contagious parasite that can infect fish regardless of their stress levels. This parasite burrows into the skin, gills, or even the eyes of goldfish and other freshwater fish, causing skin irritations. Anchor worms are about a quarter of an inch long and are visible to the naked eye. If not addressed promptly, they can penetrate deeper into the fish's organs. Treatment can be straightforward: you can manually remove the worm with tweezers or use a medication like Anchors Away, which is specifically designed to eliminate anchor worms and other parasites.

• Fish Lice

  Fish lice are visible parasites that can move freely on goldfish. These parasites cause the fish to scratch against surfaces, leading to skin irritation and sores, which can create a breeding ground for bacteria and result in secondary infections. Fish lice are highly contagious and lay numerous eggs, which hatch and find new hosts. Anchors Away is an effective treatment for fish lice. However, because this medication does not kill lice in their egg stage, repeated treatments are essential. Even after the lice seem to be eradicated, be vigilant, as un-hatched eggs may lead to re-infestation. Ensure to treat, re-treat, and maintain diligent care to fully resolve the issue.

• Columnaris

  Columnaris, often referred to as cotton mouth disease, is characterized by white, cotton-like growths on the mouth of goldfish and other freshwater fish. These growths can also affect the scales and fins. While it may resemble a fungal infection, Columnaris is caused by bacteria with a distinct columnar shape. To treat Columnaris, maintaining clean, fresh water and adding aquarium salt can be helpful. For more severe cases, copper sulfate may be a more effective treatment option.

• Melanophore Migration

  Melanophore Migration is a condition where black spots appear on an otherwise healthy goldfish. Melanophores are pigment-containing cells that control the darkness or lightness of the skin pigment, allowing for color changes and camouflage. This condition often arises from stress due to poor water quality or can be a secondary infection caused by parasites. To address Melanophore Migration, perform a water change to improve the tank environment. Once the water quality is restored, you will need to be patient as the black spots gradually disappear.