White spot disease in fish
What is white spot disease or ich
White spot infection occurs when the fish’s immune system is weakened due to stress such as temperature fluctuations, compatibility issues, or introduction to a new environment. Infected fish have small white granular lesions on the gills and fins that can spread over the entire body, giving the appearance of a pinch of salt. The initial infection can often be seen on the fins before spreading to the body.
Although infections are often seen in newly added fish, this may be due to the stress of transportation and the challenges of a new home that lower their immune systems and expose them to parasites present in established aquariums.
Their established tankmates are better able to protect themselves from these threats and thus remain symptom free, this is especially the case when nitrate levels are high. The background source of these parasites can be found in detritus and organic waste in many systems, so good hygiene and maintenance is important to prevent white spot outbreaks.
Infected individuals often close their fins and attempt to remove the parasites by rubbing against objects. Fish that have a particularly pronounced infection in the gills will quickly become listless and lose weight rapidly.
The disease is caused by a protozoan parasite that feeds within the fish’s skin and tissues covered by the fish’s mucus, largely protecting the parasite from medications.
How to treat white spot disease
The only way to stop the infection is to treat the disease for several days, as most of the parasites will have matured and left the protection of the fish’s skin during this period to multiply and have young. These juvenile parasites are vulnerable when trying to find new hosts, as they are free-swimming and can be killed with proper treatment, thus interrupting the parasite’s life cycle and ensuring that no new infections occur.
Increasing aquarium temperature can help speed up this life cycle and boost the fish ‘s immune system, but this will also affect oxygen availability at a time when gill function is compromised.
Adding additional aeration in the form of an air stone can be beneficial, especially for fish that may not appreciate the extra current generated by stronger water movement due to their reduced vigor. As some of the chemicals used in medications can lower dissolved oxygen levels, this is good practice as part of a standard treatment plan.
Water testing is also vital in determining the source of the stress: no amount of medication will cure problems caused by poor water quality.
Keep in mind that in the early days of the aquarist hobby this disease was considered lethal, despite the fact that home remedies such as salt were widely available. We urge any hobbyist to use an effective medication as soon as possible as part of their duty of care to their pets.
As the action of the parasites harms the host, a treatment containing antifungal agents will promote healing and protect against secondary infections.
Please note that chemical media such as charcoal will absorb some or all of the active ingredients in medications and must be removed before use.
The fish have numerous white spots, like grains of salt, scattered over the body and fins.
Poor water quality can be a leading cause of stress and disease in fish, so always use aquarium test kits to monitor water conditions.
Indications to cure the white point
- If you need help calculating the volume of water to treat, ask your nearest fish store. Keep in mind that aquarium decorations, such as rocks and gravel, will affect your tank’s ability to displace water; not taking this into account can cause an overdose.
- Shake the bottle well before use.
- Mix the necessary treatment dose with 1 liter of aquarium water.
- Add this diluted mixture slowly to the aquarium where the movement of the water will ensure good circulation and rapid distribution.
- Repeat the dose every other day for 7 days (ie days 1, 3, 5 and 7).
- Treatment can be repeated 7 to 10 days after the last dose. If it is necessary to repeat the treatment, make sure the diagnosis is correct, check the water quality and carry out a partial water change between treatments (up to 25%).
Dosage: 10 ml to 200 liters of aquarium water
Repeat the dose every other day for 7 days.
When used at recommended dosages, these products are safe for use with invertebrates such as shrimp and snails.
Use with freshwater manta rays (Potamotrygon) is not recommended. For sensitive species, doses may be administered in two halves added several hours apart to ensure the safest rate of dilution. Deliberate underdosing is not recommended as this may promote resistance in target pathogens.