Air bubble disease manifests as air bubbles trapped in the eyes, fins or skin of the fish. It does not include any swim bladder or buoyancy disorders. The disease begins as a series of very small bubbles, called microbubbles, that slowly form into larger, more pronounced bubbles. Microbubbles may invade your aquarium in a number of ways. In order to successfully treat the disease, the source of the microbubbles must be identified and eliminated.
What is bubble disease?
Gas bubble disease occurs when gases are oversaturated in water (dissolved beyond the normal range), forming small bubbles visible in fish eyes, fins or skin. They may also be present in internal organs. The most common gas is nitrogen, which may be a collection of small bubbles or may merge into one or two large bubbles. Carbon dioxide and oxygen bubbles are possible, but these gases are often used by fish tissues and are easy to handle.
Symptoms of bubonic disease in freshwater fish
Bubbles can be seen in the anterior chamber behind the cornea of the eye. Bubbles within the skin can be seen as external masses or can be felt by moving the hand along the fish. Bubbles can also be seen in the hyaline membrane of the fins, between the fin strips. Internal bubbles are not visible and may lead to tissue degeneration. It is very rare to have only internal bubbles and no external bubbles.
You may notice that the clarity of the water becomes cloudy. These can be tiny micro bubbles in suspension. This is similar to pouring a glass of water out of the tap too quickly. To test the clarity of the bubbles, collect a sample of cloudy water and let it sit for 30-45 minutes. If there is sediment in the water, you will notice a film at the bottom of the glass. If it is microbubbles, the water will become clear and bubbles may cling to the inside of the glass, just like champagne.
Diagnosis of air bubble disease
Most cases of bubonic disease can be diagnosed by physical examination. It is critical to evaluate all animals in the system that have potential bubble disease episodes. Aspiration will be performed to see if the bubbles are actually air or clear fluid.
To determine if there are any internal air bubbles, an x-ray or radiograph of the fish may be taken. This procedure usually requires sedation to obtain a good image.
Air bubbles may also be present in the gill tissue. This can be seen on the wet mount of the gills, a common aquatic diagnostic procedure.
Causes of air bubble disease
There are many reasons why microbubbles may be introduced into your fish system. The most common cause in home aquariums is little to no disconnect in the plumbing or filtration components. Pinholes allow tiny air bubbles to be drawn in through the movement of the water through the filtration system. Check your pump and filtration equipment to ensure that no air is entering the pump and being pressurized and blown into the aquarium. There should not be large amounts of air bubbles pumped into the water from the filter.
Another place where air bubbles can be introduced is the bottom of a high waterfall or feature. The most common situation is when a fish tank is not filled with water. The effect of mixing water from a waterfall with lower water can also produce bubbles of various sizes. Air bubbles may vary depending on water temperature and bioburden.
Sudden changes in water temperature can cause bubbles to form because the partial pressure of the gas varies with the water temperature. This is most common when you add water to the system that is significantly warmer or cooler than the current water temperature. Unless you are intentionally controlling the temperature of your system, it is critical to always test the water temperature and try to match the new water to the current water temperature whenever you make a water change. If you are using water changes to alter the temperature of your tank or pond, take your time so as not to stress the fish.
Gas supersaturation in water occurs when the total pressure of the gas in the water is higher than the surrounding atmospheric pressure. Depending on how your system is set up and the atmosphere in the room around your aquarium, you may have microbubbles forming from simple changes in atmospheric weather. If you suffer from bubble disease with no clear cause, you may need to record the air pressure around your tank for a few days to see how the bubble disease begins or dissipates.
Treatment of air bubble disease
The most important treatment for air bubble disease is to determine the cause of the microbubbles in your system. It may not be as simple as you think!
Since there are many potential causes, it is vital to eliminate them to prevent the disease from getting worse. Check aeration, pumps, water flow back into the aquarium and look for small air bubbles in plants, decorations or on the walls of the tank. Temporarily shutting off the filter and looking for bubble formation may help determine if the filter is the cause of gas supersaturation. Evaluate all animals in the system to ensure that all symptomatic animals are being treated effectively. Your veterinarian may be able to remove air bubbles by aspirating them with a very small needle and syringe. Antibiotic therapy is a common addition to any bubble disease treatment regimen. If your aquatic practitioner has access to a pneumatic chamber, one will be used in some cases.
Your veterinarian may be able to remove air bubbles by aspirating them with a very small needle and syringe. Antibiotic treatment is a common addition to any bubble disease treatment regimen. If your aquatic practitioner has access to a pneumatic chamber, it will be used in some cases.
How to prevent air bubble disease
In order to successfully prevent bubble disease, it is important to assess all potential causes and eliminate them from the system.
Ensure that all piping and filter components are properly connected and sealed.
Keep the water level at the proper level and fill up as needed. Keep track of your refill schedule so you can catch leaks early.
Always check the temperature of the system and the new water added during the water change.
