Diseases

Discus Fish Diseases

Do your discus fish seem listless? Do they have markings on their bodies that weren’t there before? These could be signs of disease.

One time, I noticed that one discus fish was swimming erratically and had spots on its body. A few days later, half of my discus fish were dead. It was a painful lesson that I learned the hard way: not all discus fish diseases are visible to the naked eye.

However, don’t worry. In this article, I’ll share with you the most common discus fish diseases and how to treat them.

Common Discu Fish Diseases

Before we get into the fish disease, it’s important to note that discus fish suffer from two types of illness: external and internal.

As you can guess, external diseases are visible on the discus fish’s body. These diseases are typically caused by parasites or injuries.

On the other hand, internal diseases are often harder to spot because discus fish isn’t visible on the outside.

Now that we got that out of the way, let’s take a look at some of the most common diseases that affect discus fish!

External Diseases

Toxic Aluminum

This disease takes place in your tank whenever the pH level is greater than or less than 8 and 5.5, respectively.

Also, if you use water with high levels of aluminum, it can damage your discus fish’s gills and cause them to suffocate, which in turn will make toxic aluminum appear in your tank.

Causes

  • Low or high pH levels
  • Using aluminum products in the aquarium water

Symptoms

  • A sudden change in the behavior of your discus fish
  • Floating at the top of the aquarium, dazed and confused

Treatment

Prevention

  • Check the pH level regularly and make sure the pH level is between the desired range
  • Verify that no aluminum goods are used in the aquarium water (unless the discus fish has been manufactured especially for aquarium use)

Fungal Infections

Fungal infection is a typical condition affecting Discus fish, particularly their external tissues.

This disease develops if the fungus spores present in the water infect your fish when their immune system is weak or if the discus fish has an open wound.

Unfortunately, this infection is unavoidable since it develops as a consequence of an injury or a parasitic invasion of the fish’s skin.

However, the worst aspect is that this disease can kill your fish in just a few days if you don’t treat it in time.

Causes

  • Spores of existing fungus in the aquarium water
  • Wounds or fractures on the fish’s skin
  • Bad water quality
  • Other fish with recurring fungal infection

Symptoms

  • A cottony or feathery attachment surrounds the break/wound on the fish’s body

Treatment

  • Use Antibiotics such as Triple Sulpha and Tetracycline

Prevention

  • Treat wounds and fractures on the fish’s skin as soon as possible
  • Maintain your water quality
  • Remove any dead fish as soon as possible
  • Use antifungals
  • Add some salt to your aquarium

Parasitic Anchor Worms

The Anchor Worm is a type of parasitic crustacean that belongs to the Lernea genus. It bores its head into the fish’s muscle tissue, thus causing a lot of irritation.

Causes

  • Bad water quality
  • The addition of a new fish in the tank that already has the worm
  • Skipping appropriate quarantine
  • Aquatic plants in the tank

Symptoms

  • Skin irritation
  • The parasite’s whitish-green threadlike body can be seen sticking out from the fish’s skin

Treatment

  • Apply potassium permanganate dips or salt dips
  • Use antiparasitic
  • Apply topical antibiotic ointment to the infected area
  • Use organophosphates or diflubenzuron with the veterinarian’s consent

Prevention

  • Quarantine any fish infected with the Anchor Worm
  • Maintain clean and high-quality water

White Spot Infections

The white spot, or “Ich,” is a deadly tropical fish disease that discus fish breeders have to deal with quite frequently.

Since this illness has a high transmission rate and an outstanding mortality rate. If you don’t act quickly, it can kill all the fish in your tank within a short period of time.

However, the good news is that this disease is relatively easy to spot since it manifests itself as white spots on the fish’s body.

Causes

  • A microscopic parasite called Ichthyophthirius multifiliis

Symptoms

  • Swimming around erratically
  • Lethargy and emaciation
  • Tiny white spots & patches appear on the gills and the rest of the body
  • Loss of appetite

Treatment

  • Perform a partial water change every few days
  • Keep the aquarium lights off for as much of the day as feasible (this will prevent the outbreaks if you don’t have medication available)
  • Use Ich medication such as Acriflavine

Prevention

  • Perform water changes on a weekly basis
  • Maintain excellent water quality
  • Don’t overcrowd the tank

Cloudy Eye Infection

Cloudy eye infection is a typical eye fungus disease that can damage the fish’s pupil, so it can go blind.

Causes

  • Bacterial infection
  • Parasitic infection
  • Poor water quality
  • Eye injury
  • Physical stress is caused by illness and fish transport

Symptoms

Treatment

  • Apply a topical antifungal medication like API Fungus Cure
  • Quarantine the infected fish

Prevention

  • Do frequent water testing
  • Perform regular water changes
  • Maintain proper water temperature
  • Adjust proper pH level
  • Maintain high water quality
  • Replace the carbon filter regularly

Columnaris Disease

Columnaris, (mouth and fin rot) is a bacterial infection that can be fatal to aquarium fish.

Even though it’s been around since the 1940s, when antibiotics were not common among hobbyists, it is still causing problems in our community today.

Causes

  • Poor water quality
  • Low Oxygen levels
  • Sudden changes in temperature or pH
  •  Overcrowding
  • Adding new fish that are infected with the disease
  • It can occur as a secondary infection from other diseases, such as fin rot and Velvet (gold dust disease), or due to aggressive behaviors

Symptoms

  • Small white dots on the fins, these spots will grow in size then discus fish will vanish completely
  • Redness
  • Inflammation

Treatment

  • Remove the infected fish to a separate aquarium
  • Use an antibiotic solution, such as Furan-2 and Furan-3

Prevention

  • Make regular water changes
  • Vacuum the gravel regularly, as it can get clogged with detritus and algae
  • Replace 20-30% of your filter media every week or two (or more if necessary)
  • Don’t allow your fish to go hungry and provide them with plenty of food
  • Remove any dead plants

Discus Plague

The discus plague (Black Disease) is a viral infection that results in fish having black spots on their bodies.

It’s a contagious disease that only affects discus and can quickly spread from tank to tank or fish to fish.

Causes

  • Airborne virus
  • Introducing an infected discus fish to the aquarium.
  • Aquarium plant or equipment that carries the virus

Symptoms

  • Rubbing against objects
  • Rapid and heavy breathing
  • Clamping of fins
  • Black spots on the skin
  • Fish trying to hide in the dark areas
  • Loss of appetite
  • Cloudy and/or smelly water
  • Jerky swimming motions

Treatment

Although there is no official cure for Discus Plage sickness, there are a few general treatment methods that could be useful, including:

Prevention

  • Maintain high water quality
  • Do not add any fish with the discus plague, since discus fish may serve as a vehicle for the disease’s transmission
  • Treat skin injuries and wounds right away
  • Quarantine the infected fish

Tail and Fin Rot

Fin and tail rot disease is caused by bacteria called Aeromonas which enter the discus body through wounds and open sores.

Causes

  • Poor water quality
  • Sudden temperature changes

Symptoms

  • Holes in the fins or discoloration of them
  • Dark spots appear on the body of the fish

Treatment

  • Use antibiotics if the infection is relatively mild
  • If the condition is more severe, it will necessitate more intensive treatments that are given through intramuscular injections or intravenously

Prevention

  • Regularly check the water quality in the tank
  • Keep your pet away from toxic chemicals (such as formalin)

Internal Diseases

Loss of Balance or Headstanding

You can spot this disease when you see your fish doing weird things like standing on their heads or balancing themselves precariously on objects in the tank.

Causes

  • Poor water quality
  • Digestive system blockages
  • Swimbladder trouble
  • Blood flagellates

Symptoms

  • Weird flip-flop antics in the tank

Treatment

  • Adjust the proper water parameters
  • Treat the infected fish by adding salt and antibiotics to the aquarium
  • Change the water more often

Prevention

  • Always check your water parameters
  • Do regular water changes

Fish Tuberculosis

Fish tuberculosis is a secondary disease that is caused by the tuberculosis mycobacteria present in the aquarium gravel, food leftovers, and other debris.

However, you must handle this fish sickness with care, as the bacteria might infect humans through open wounds and cuts.

Causes

  • Poor living conditions
  • Overcrowding
  • Infected fish

Symptoms

  • Tuberculosis is bloating
  • Emaciation
  • Jerky movements
  • Skin sores
  • Popeye
  • Loss of appetite
  • Odd spinal curvatures

Treatment

  • Provide them with Vitamin B-6 and Kanamycin Combination
  • Quarantine the infected fish
  • Remove all the inhabitants from the tank, and clean all the decorations and accessories

Prevention

  • Avoid overcrowding the tank
  • Avoid introducing sick fish into the tank
  • Do regular water changes

Dropsy and Popeye

Dropsy and popeye happen when there is fluid retention either behind the eye or along the spine. This makes the eyes bulge outwards.

Causes

  • Bacterial infections
  • Physical damage to the fish’s eyes
  • Poor nutrition
  • Ammonia spikes

Symptoms

  • The eye of a fish may become bloated and protrude from the head
  • It can frequently get worse until the eye is completely out of its socket
  • If one eye becomes blind, the other eye will work harder to see until it too becomes affected by popeye

Treatment

  • Move the sick fish to a separate tank and treat them with Kanamycin sulfate or Nitrofurazone according to a prescription
  • If there are no results after using Kanamycin sulfate or Nitrofurazone, add 1 tbsp of aquarium salt for every 5 gallons
  • Once you’ve treated your fish, carefully return them to the primary aquarium and watch for any popeye symptoms to reappear
  • Repeat therapy and use 1 tablespoon of aquarium salt per 5 gallons if the popeye reappears

Prevention

  • Provide your discus with the correct water parameters
  • Use a filter for biological filtration, such as an under gravel filter or sponge filter.
  • Feed your fish a high-quality food
  • Change about 20% of the water in the aquarium every week
  • Vacuum the gravel with a siphon or gravel vacuum
  • Remove any dead animals or decomposing plant material in the tank

Hexamitiasis

This internal protozoan infection can spread quickly in an overcrowded or poorly maintained tank.

Causes

  • Overcrowding
  • Poor water conditions
  • Nutritional deficiencies
  • Stressful situations like bullying by other fish

Symptoms

  • Whitish feces with slimy textures
  • Unusual fish behavior like swimming backward
  • Excessive hiding
  • Emaciation, and loss of appetite
  • Lethargy
  • Dimness of skin and eyes

Treatment

  • Isolate the infected fish
  • Use antibiotics such as Metronidazole
  • Make 50% water changes every day
  • Keep the water temperature between 33.33°C and 37.78°

Prevention

  • Always check your water parameters
  • Do regular water changes
  • Avoid overcrowding
  • Quarantine the new fish before adding it to your aquarium

Tapeworms

Tapeworms are huge worms that weaken fish by leaving holes in their bodies and can be deadly if left untreated.

Even though discus fish doesn’t kill the fish directly, the wounds the discus fish leaves behind make them vulnerable to parasite attacks.

Causes

  • Poor water quality
  • Poor diet
  • The introduction of a new sick fish to the tank

Symptoms

  • Sleepiness and lethargy
  • Problems with the digestive system in older fish
  • Bodyweight loss

Treatment

  • Quarantine the infected fish
  • Use antibiotics such as Praziquantel

Prevention

  • Keep the tank clean and sanitary
  • Perform regular water changes
  • Quarantine the new fish until you’re sure discus fish is not sick

Head and Lateral Line Erosion (HLLE)

HLLE is classified as chronic but nonfatal. This illness can make your fish anorexic and increase their risk of contracting secondary bacterial infection and parasitic diseases.

Causes

  • Poor water quality
  • Poor diet
  • Activated Carbon

Symptoms

  • Skin de-pigmentation (loss of color)
  • Small craters (holes) form near the head and a lateral line on the body of the fish

Treatment & Prevention

  • Feed your fish a varied diet that includes seaweed and Selcon’s vitamin supplement to promote healthy growth
  • Keep your water parameters within the safe range
  • Use high-quality carbon
  • Reduce flow rates to avoid generating abrasive particles into the water supply

FAQS

How Do I Know If My Discus Fish Is Sick?

Generally, discus fish show some physical signs when discus fish is sick. Some popular signs are:

  • Loss of appetite
  • Loss of coloration or pigmentation
  • Black feces or spots on the body or fins
  • Hiding in a dark place
  • Darting back and forth

Why Is My Discus Fish Getting Sick?

The common reasons behind a discus fish getting sick are:

  • Poor water quality
  • Ammonia buildup
  • Introducing sick fish to the tank
  • Overfeeding
  • Poor diet

Why Is My New Discus Fish Sick?

One of the most typical reasons a new discus fish gets ill is because you introduced it to the aquarium without being acclimated

It’s best to wait until the ammonia and nitrites dip down to zero. This could take 3-6 weeks, depending on the size of the tank and if there are other fish already living in it.

Why Is My Old Discus Fish Getting Sick?

Old fish have a weak immune system and are more prone to diseases. Thus, discus fish is more likely to get sick than younger ones.

How Can I Prevent a Disease From Spreading?

To prevent diseases from spreading:

  • Clean your aquarium regularly
  • Change the water frequently
  • Keep your fish tank well-ventilated
  • Use a filter and aerate the water
  • Quarantine new fish before adding them to the main tank
  • Conduct regular check-ups on your fish
  • Clean out the gravel
  • Chang out the filter cartridge

Last Words

Discus fish are beautiful and peaceful creatures that make a great addition to any aquarium. However, discus fish is very sensitive and can get sick easily if exposed to poor water quality or other stressors.

Just remember, the best way to prevent disease is to keep your aquarium clean and well-maintained. By following these simple tips, you can help ensure your fish stay healthy and happy for years to come.

I hope you enjoyed this article. If you have any additional questions or tips, please feel free to leave them in the comments below. Thanks for reading!