Please help! Fin rot starting from middle of fin expanding out?

I have had my betta for four months in a cycled 5 gallon filtered/heated tank with live plants. A month ago his dorsal fin began to shrivel and a black spot appeared in the middle (see pictures). I think it is fin rot, but all the sources I've seen on fin rot says it starts at the edges of the fins and not in the middle or near the base. It wasn't getting better with daily water changes. I have been dosing Paraguard for the last week, but it doesn't seem to be doing much. In the last two days my betta has stopped swimming and eating. He seems like he is in pain when he swims up to the surface for air. The black area is getting noticeably bigger with each passing day and has spread to the upper middle edge of his tail fin. I am worried my betta will die very soon. Any help at all in diagnosing this will help me decide what treatment I can pursue. Please help me!!!!

 

Hi kr128,

I'm sorry this happening to your fish! This sounds like a pretty bad bacterial infection that will need immediate treatment. I highly recommend you start treating with methylene blue. Methylene blue is a potent yet gentle medication. Its a disinfectant, anti fungal and anti parasitic, so its pretty well rounded. You treat the fish by removing it from the water, taking a cotton swab dipped in methylene blue and dabbing it on the affected area, rinsing the fish in a bowl of tank water then returning it to the tank. Methylene blue also increases oxygen flow to the blood, and promotes healing. It should clear up the infection fairly quickly.

Methylene blue will only work, however, if the water quality is pristine. You need to be conducting daily partial water changes of at least 30%. Water changes help boost the fish's immune system and promotes healing as well. They really do work wonders for a fish.

In order to figure out why this happened, could you let us know your readings for ammonia, nitrite and nitrate? How often do you do water changes and how much do you replace?

Hope this helps and please feel free to ask any additional questions you may have!

 

Thank you SO much for your reply!!! I am rush-ordering methylene blue now! Praying it helps!! I am also getting some Kanaplex in the mail tomorrow. Do you think I should use that along with the methylene blue or not use it at all? I don't want to stress my betta out any more than necessary.

My current water parameters are Ammonia and nitrites 0, nitrates ~5 measured with API test kit, but they have likely not been ideal in the past. I received my betta as an office Christmas gag gift, and while I knew he couldn't live in the cup he came in I had no knowledge of the cycling process (or anything about keeping an aquarium) when I put him in his tank. From the beginning I was doing weekly 20% water changes, but I didn't buy the test kit until way too late, and am sure that I have had ammonia spikes that were harming my betta. More recently, I had a white feathery growth in my tank that wasn't going away with daily water changes. I did a 100% water change around 10 days ago and boiled my tank decor to get rid of it and haven't seen signs of it since. I have been doing 20% water changes every day since my betta's fin started looking raggedy and added some Indian almond leaves.

I was reluctant to accept my gifted betta, but was reassured that he would be a "low-maintenance" pet. Which, after educating myself, I now know is absolutely not true. I just wish my ignorance didn't have to come at his cost. He was so vivacious when I first put him into his tank, and it is heartbreaking to see him suffering. Thank you again for your reply. I really appreciate it.

 

I would not use Kanaplex quite yet. Mixing medications can be extremely stressful for the fish.

If your water quality has not always been great, that is likely where the infection stemmed from. Fortunately, you have a chance to correct this by keeping the water quality pristine while he is in treatment. And afterwards, of course. This should prevent any infections from arising in the future.

Keep us updated on how he is doing!

 

Hi kr128,

I'm sorry this happening to your fish! This sounds like a pretty bad bacterial infection that will need immediate treatment. I highly recommend you start treating with methylene blue. Methylene blue is a potent yet gentle medication. Its a disinfectant, anti fungal and anti parasitic, so its pretty well rounded. You treat the fish by removing it from the water, taking a cotton swab dipped in methylene blue and dabbing it on the affected area, rinsing the fish in a bowl of tank water then returning it to the tank. Methylene blue also increases oxygen flow to the blood, and promotes healing. It should clear up the infection fairly quickly.

Methylene blue will only work, however, if the water quality is pristine. You need to be conducting daily partial water changes of at least 30%. Water changes help boost the fish's immune system and promotes healing as well. They really do work wonders for a fish.

In order to figure out why this happened, could you let us know your readings for ammonia, nitrite and nitrate? How often do you do water changes and how much do you replace?

Hope this helps and please feel free to ask any additional questions you may have!

I actually do have some questions about the methylene blue application. Do I need to have him in shallow water when I apply it? Do I need to try to isolate the methylene blue to only the affected area or is it okay if I let the chemical diffuse through the water and he "bathes" in it for a few seconds/minutes?

 

There are actually 3 different ways you can treat with methylene blue - a swab, a dip and a bath. I always go for the swab method when I can. Its the only way to get highly concentrated medication directly onto the affected tissue. When you do this, you'll want the fish out of water. The swab only takes a few seconds, because all you're doing is dabbing the methblue on the fin. Then immediately rinse the fish in a bowl of tank water and then return it to the tank. Those few seconds the methblue was on will be more than enough to kill any bacteria that was on there. Just be careful you don't get any concentrated methblue in the eyes or gills.

A dip and a bath are similar, they dilute the methblue and treat the whole body. A dip is more concentrated than a bath, and a dip takes a few seconds while a bath takes a few minutes. The only downside to these is that you aren't getting super concentrated medication right where the infection is, so its possible you don't treat it fully.

If you're uncomfortable doing the swab, however, we can definitely look into a dip or bath. Just let me know what you want to do.

 

Hi KayBee3,

A day after doing the swab on the affected area of my betta's dorsal fin, the black area spread to the tip of the fin, and the fin fell off! It is just a nub now. The good news is that my betta started swimming and eating again immediately after the fin fell off, and I don't see any more signs of spreading necrosis. I am still doing 20% water changes every day and keeping a close eye on my little friend. I don't know if his fin will ever grow back, but I am hoping he will recover somewhat.