Columnaris in Betta Fish (Cotton Wool Disease): Vet-Approved Signs, Causes, Treatment & Prevention

While columnaris is certainly an unsightly and worrying condition to find in your Betta fish, it is treatable (provided you act fast). That said, prevention is always better than the cure, and understanding the ways to prevent the disease is as important as knowing how to treat it. In general, Bettas are hardy, resilient fish that can live happy and healthy lives as long as they are provided with a clean tank, a balanced diet, and optimal water parameters.

In this article, we look at what exactly columnaris disease is, what causes it, how to treat cotton wool disease in your Bettas, and how to prevent it. Let’s get started!

What Is Cotton Wool Disease?

Columnaris goes by several different names, including cotton wool disease, cotton mouth disease, and saddleback disease, and it is a fairly common condition among freshwater aquarium fish. Despite its cotton-wool, “fungal-like” appearance, columnaris is not caused by a fungus, but rather by a bacterium called Flavobacterium columnare. It can affect all species of fish in a freshwater tank, not just Bettas, so you’ll want to get rid of it as soon as it appears. Unfortunately, it causes death rather rapidly (especially in a tropical aquarium) and death usually occurs in 2-3 days if no treatment is attempted.

What Causes Cotton Wool Disease?

Flavobacterium columnare, the bacteria responsible for cotton wool disease, is so common that it actually lives in most freshwater tanks, unbeknownst to the owner. If your fish live in a healthy environment, with a healthy diet and strong system, they can live with the bacteria their entire lives without it affecting them.

That being said, small changes can cause infection in your fish, including:

Signs of Cotton Wool Disease

Columnaris is fairly easy to identify, although it can present itself in various ways on your fish. Other than the obvious cotton wool-like growth that shows up on your Betta’s gills (at which stage, the disease is already fairly advanced) there are several other identifiers of this disease, including:

The 3 Steps for Treating Columnaris in Bettas

Now that you know the signs to look out for and the potential causes of cotton wool disease, let’s look at how to treat it effectively.

Step 1: Quarantine

The first step in the treatment of your Bettas is to move them to a separate quarantine aquarium. Bacteria thrive in warmer temperatures, so you’ll want the water temperature of your quarantine tank to be slightly lower than normal. Lowering the aquarium temperature to 75 °F (24 °C) is a must, since columnaris is much more virulent (causes quicker death) at higher temperatures, especially 85–90 °F (29.4-32.2 °C).

Step 2: Medication

Next, you’ll need to add a suitable aquarium antibiotic to your Betta’s quarantine tank. Antimicrobial medicine which contains nitrofurazone and kanamycin are the preferred options to treat columnaris. They should ideally be used together. There are several suitable medications to choose from, but API’s Furan 2 is a great choice as it contains nitrofurazone. KanaPlex contains kanamycin, which is a great adjunctive option for treatment. Simply follow the instructions on the bottle, or speak to a professional if you are unsure. Besides using an antibiotic, you can add aquarium salts, which will help reduce stress and boost your Betta’s immune system.

Step 3: Water change

While your Betta is being treated in the quarantine tank, you’ll want to perform a full water change on their main tank. A 25% water change every day or two is a good way to rid the water of any remaining bacteria before you return your Betta and will give you a chance to thoroughly clean the tank and better the chances of your Betta’s recovery.

If you have caught the disease early enough and given your Betta treatment, they should recover quickly and easily. If they are not showing any signs of getting better, the disease may have progressed too far. Additional options can be discussed with your aquatic veterinarian in this case.

How to Prevent Columnaris in Your Aquarium

As the adage goes, prevention is better than the cure, and you’ll save yourself a great deal of time, money, and stress by doing your best to avoid your Betta getting the disease in the first place. While there are never any guarantees, here are simple methods that will go a long way in preventing your Betta from getting sick:

Final Thoughts

Cotton wool disease is a potentially deadly issue in freshwater tanks, so if you notice it in your Betta, you’ll need to treat it as soon as possible. Treatment is fairly easy, and if you catch the disease early enough, your Betta will most likely be fine. Still, prevention of the disease is easier than the cure. Making sure your aquarium is clean, changing the water regularly, avoiding overcrowding, and feeding your Bettas a nutritious diet will go a long way in keeping their immune systems healthy enough to fight off the bacteria.

Featured Image Credit: yin800321, Pixabay