Cotton Mouth (Columnaris)

What is Cotton mouth?

Most Columnaris infections are external and present first as white or greyish white spots on the head and around the fins or gills. The lesions may first be seen only as a paler area that lacks the normal shiny appearance of the rest of the fish. As the lesion progresses it may become yellowish or brownish in colour and the area around it may be tinged red.

What are the causes of cotton mouth?

- The bacteria are most likely to infect fish that have been stressed by conditions such as poor water quality, inadequate diet, or stress from handling and shipping.

- Columnaris can enter the fish through the gills, mouth, or via small wounds on the skin. The disease is highly contagious and can be spread through nets, specimen containers, and even food.

How to treat Cotton Mouth:

- Check your water conditions when cotton mouth is detected. Chemistry as well as pH and water temperature.

- Perform a 30% to 50% water change before the treatment.

- Ensure you remove the filter carbon before using any treatments.

- The following medications will help cure the infection. Furan 2, Melafix, aquarium salt, or a vet prescribed antibiotic.

- Add aquarium salt 1 tablespoon per 20L. Make sure 50% water changes are done daily using this method.
Use this treatment on bettas or other surface breathing fish. (Caution with those scaleless fish. e.g. clown loach)

- After the treatment, another 50% water change must be made to help clear the medicine and thereafter 10-15% every other day for a week while monitoring the fish.