Fin Rot in a Betta

Question
Hi Amber,

We have had our betta for almost two years now.  About two months ago, he lost his top fin, rather rapidly.  I treated him with two series of maracyn two.  I waited about a month and he still had not improved.  I treated him again with the maracyn-two.  His fin still has not grown back and now it looks as if he is geting a big hole in the top of his body.  You can see a dark black ring covering the top of his body where the fin used to be.  It keeps growing larger, down to the middle of his belly.  He eats and swims around happily.  Is he is pain and how can I take care of him?  Thank you so much for your help.

Sherry

Answer
Hello Sherry-

I'm so sorry about your little one's fin loss!
This sounds like a very extreme case of fin rot.
I would recommend a strong dose of aquarium salt, and an increase of 4-5 degrees in his water temperature. If the dark black ring looks bacterial (or like a fungus) keep up this treatment and try Maracyn One to see if you get better results. But, also bear in mind that some bettas change coloration over the years and the dark splotch may just be his natural coloring. If your betta is still doing fine after the treatments and there is no change in the black spot, back off the meds but keep up with the salt dosage. It's hard to tell if this is bacterial or not without seeing the spot - my e-mail is abworman@purdue.edu if you manage to get a good picture of this.

Hope this was helpful!
-Amber Worman