When my axolotl had a fungal infection (my fault, I didn't do frequent enough water changes and his sand went bad) it appeared as white blobs on his gills that slowly ate away at them. I cured it by scrubbing his tank and accessories clean, and using some "Myxazin" which I'd seen recommended on a post on this site. I think you're only meant to use half the dose stated on the bottle however, as axolotl are sensitive things! Hope that helps.