Viral betta diseases can be highly contagious; but even if they’re not, they can be fatal to your fish if left untreated for any considerable amount of time. Here are just three of the most common viral diseases that afflict bettas, and their treatments or control measures.
IPN – Infectious Pancreatic Necrosis
This is one of the most contagious and fatal betta fish diseases that may affect your fish. There is currently no known treatment for IPN; in all likelihood, the fish will die of the disease but, resilient as they are, some might survive. Surviving fish should ideally recover within one or two weeks. If any of your bettas are affected by this, frequent water changes and quarantining the affected betta will stop the infection from spreading to your other pets. Unfortunately, that’s about all you can do as a pet owner.
Systemic Iridovirus
Again, probably the only cure for this viral infection is preventive action. The symptoms of this disease resemble lymphocystis, but become more acute over time, resulting in the body of the fish bloating (because the disease affects the kidneys), and the eyes starting to protrude (also known as “pop-eye”). There are studies that show that this type of infection progresses at its most rapid rate in water that is between 10 and 12 degrees Celsius, so maintaining the water temperature at a much higher level should ideally prevent the spread of this pathogen. In colder climates this is a challenge, so an aquarium should be installed to ensure that it doesn’t become cold enough for the virus to start infecting your bettas. In addition to helping deal with viral infection, warmer temperatures can also prevent the onset of protozoan diseases.
Lymphocystis

This is a stress-related disease that is caused by a type of iridovirus. High levels of stress may cause this condition, the symptom of which is the appearance of strawberry-like swellings on the fish’s body.
Fortunately, when stress levels are reduced, the condition has been known to go away, and the disease is rarely fatal to bettas. Avoiding overcrowding your aquarium is probably the best preventive measure for lymphocystis because these fish are usually shipped as stock, causing the stress in the first place.
Several other types of viral and bacterial diseases can affect betta fish, but knowing how to prevent and deal with these three conditions will ensure that you are aware of possible dangers. Trial and error are often the best ways to arrive at a good solution in terms of water quality, changing routines and even the optimal number of fish to keep in an aquarium of a particular size; however, if you know the basics then the trial and error method won’t lead to losing fish in the process of learning how to take care of them. The better educated you are about common infectious diseases, the better for your bettas.