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My betta has a white scab on his fin and body. Is it an infection?

Updated On September 23rd, 2025

Can you tell us what may be wrong with our betta? The top fin has what looks like a white scab but extends down his sides.

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1 Answer

Most Helpful Answer

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Answered By Dr. Massimo Orioles, DVM, Cert AVP, MRCVS

Veterinarian

Published on April 4th, 2018

That could be due to a fungal or bacterial infection. A radical and logic approach is needed anyway as different factors may contribute to the onset of an infection. Begin by submitting a water sample for quality testing. Most pet stores will do this for free or a nominal fee. Clinical examination should always include a water quality check, even if you have done so already. Water testing should be performed with a quality test kit, measuring NH4, NO2 and NO3. High ammonia levels, PH imbalances may be responsible for these signs. Oxygen concentration and quality of the filters should be determined as well. If water quality is good and there are no major imbalances, your fish should get examined to look for any sign of bacterial/fungal infection and eventually water should be treated. Hope this answer was helpful, but please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further.

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